TWI820786B - Yttria-zirconia sintered ceramics for plasma resistant materials and method of making the same - Google Patents

Abstract

Disclosed is a ceramic sintered body comprising yttrium oxide and zirconium oxide wherein the ceramic sintered body comprises not less than 75 mole % to not greater than 95 mole % yttrium oxide and not less than 5 mole % to not greater than 25 mole % zirconium oxide, wherein the ceramic sintered body comprises porosity in an amount of less than 2% by volume, wherein a density of the ceramic sintered body does not vary by more than 2% relative to theoretical density across a greatest dimension. The ceramic sintered body has a grain size of from 0.4 to less than 2 um as measured according to ASTM E112-2010. The ceramic sintered body may be machined into plasma resistant components for use in plasma processing chambers. Methods of making are also disclosed.

Description

Yttria-zirconia sintered ceramics for plasma-resistant materials and manufacturing method thereof

The present disclosure generally relates to a plasma-resistant ceramic sintered body including yttrium oxide and zirconium oxide and a method of making the same, and more specifically to a plasma-resistant chamber assembly made from the sintered ceramic body .

Semiconductor processing requires the use of halogen-based gases as well as oxygen and other process gases combined with high electric and magnetic fields to create an environment suitable for plasma etching and deposition processes. These plasma etching and deposition environments are performed in vacuum chambers for etching and depositing materials on semiconductor substrates. The harsh plasma environment necessitates the use of highly plasma-resistant (corrosion and erosion-resistant) materials for components in the processing chamber. These chambers include components such as disks or windows, liners, gas injectors, rings, and cylinders that confine the plasma over the wafer being processed. Such components have been formed from materials that provide corrosion and erosion resistance in plasma environments and have been described in, for example, US 5,798,016, US 5,911,852, US 6,123,791, and US 6,352,611. However, these components used in plasma processing chambers are continuously attacked by the plasma, and as a result, corrosion, erosion, and roughening occur on the surfaces of the chamber components exposed to the plasma. This corrosion and erosion causes wafer-level contamination by releasing particles from the device surface into the chamber, resulting in loss of semiconductor device yield.

Rare earth oxides, and especially sintered bodies of yttrium oxide Y ₂ O ₃ and zirconium oxide ZrO ₂ , are known to be chemically inert and exhibit high resistance to plasma (corrosion and erosion). However, there are several disadvantages associated with the use of rare earth oxides, particularly sintered bodies of yttria and zirconium oxide.

Yttria and zirconia systems are known to be difficult to sinter to the high densities required by traditional methods, resulting in low density and significant porosity in the final part or assembly. The remaining porosity and low density lead to accelerated corrosion during the plasma etching and deposition processes, thereby degrading the plasma resistance of the device. In addition, sintering yttria and zirconia generally requires high temperatures of about 1800°C or higher for an extremely long period of time. High temperatures and long sintering durations lead to excessive grain growth, which adversely affects the mechanical strength of the yttrium oxide and zirconia bodies. High-purity powders of yttria and zirconia pose challenges for sintering to the high densities required for use in semiconductor plasma processing chambers. Specifically, the high sintering temperatures and plasma-resistant material properties of yttria and zirconia pose challenges in sintering to high densities while maintaining the necessary high purity. To promote the densification of yttrium oxide and zirconium oxide bodies used as plasma chamber components, sintering aids are often used to lower the sintering temperature and promote densification. However, the addition of sintering aids effectively reduces the corrosion resistance and erosion resistance of yttrium oxide and zirconium oxide materials, and increases the possibility of impurity contamination at the semiconductor device level.

Films or coatings of rare earth oxides such as yttrium oxide and zirconium oxide are known to be deposited by aerosol or plasma spraying techniques onto a substrate or on top of a substrate formed of a different material than yttrium oxide and zirconia are low in price and high in strength. However, these methods are limited in the film thickness that can be produced, exhibit poor interfacial adhesion strength between the rare earth oxide film and the substrate, and have high porosity levels, typically around 5% to 50%. time, causing particles to fall off into the processing chamber.

Attempts to fabricate solid ceramic bodies made from rare earth oxides such as yttria-zirconia for use in large-scale corrosion-resistant components have had limited success. Solid components of approximately 100 mm in diameter or larger that can be handled and used as part of the chamber wall without cracking or cracking are difficult to produce beyond laboratory scale. This is due to the fact that yttrium oxide and zirconium oxide generally have low density and sintering strength. To date, attempts to fabricate large yttria-zirconia components have resulted in high porosity, low density, cracking, and poor usability in corrosion-resistant applications. There may currently be no commercially available large-scale yttria-zirconia solid sintered bodies or components with diameters of approximately 100 mm to 622 mm available for semiconductor etching and deposition applications.

Therefore, there is a need in this technical field for a plasma-resistant ceramic sintered body that has high density, low porosity, high purity, and high mechanical strength, and provides enhanced corrosion resistance and corrosion resistance under plasma etching and deposition conditions ( Plasma resistance), especially suitable for manufacturing large-sized components (diameter 100 to 622mm).

These and other needs are addressed through various embodiments, aspects, and configurations as disclosed herein:

Embodiment 1. A ceramic sintered body comprising yttria and zirconium oxide, wherein the ceramic sintered body contains no less than 75 mol% to no more than 95 mol% of yttrium oxide, and no less than 5 mol% to no more than 25 mol% zirconia, wherein the ceramic sintered body contains an amount of porosity less than 2 volume %, and wherein the density of the ceramic sintered body does not vary by more than 2% relative to the theoretical density in the largest dimension, wherein the ceramic sintered body The body has an average particle size of 0.4 to less than 2um as measured according to ASTM E112-2010.

Embodiment 2. The ceramic sintered body of Embodiment 1, having at least one surface comprising yttria and zirconium oxide, wherein the at least one surface is polished and includes an amount of less than 2% based on the pore area of the at least one surface. Porosity.

Embodiment 3. The ceramic sintered body of Embodiment 2, wherein the porosity measured on the polished surface extends throughout the ceramic sintered body.

Embodiment 4. The ceramic sintered body of any one of the aforementioned embodiments 1 to 3, which contains yttrium oxide in an amount of not less than 75 mol% and not more than 85 mol%, and not less than 15 mol% and not more than 85 mol%. Zirconia in an amount greater than 25 mole %.

Embodiment 5. The ceramic sintered body of any one of the aforementioned embodiments 1 to 4, which contains no less than 77 mol% to no more than 83 mol% of yttrium oxide, and no less than 17 mol% to no more than 23 mol%. Mol% of zirconia.

Embodiment 6. The ceramic sintered body of any one of the aforementioned embodiments 1 to 5, which contains no less than 78 mol% to no more than 82 mol% of yttrium oxide, and no less than 18 mol% to no more than 22 mol%. Mol% of zirconia.

Embodiment 7. The ceramic sintered body of any one of Embodiments 4 to 6, having a density of 5.01 to 5.13 g/cc measured according to ASTM B962-17.

Embodiment 8. The ceramic sintered body of any one of Embodiments 4 to 7, which has a hardness of not less than 8.5 to 14.5 GPa measured according to ASTM standard C1327.

Embodiment 9. The ceramic sintered body of any one of the preceding embodiments 1 to 8, excluding HfO2 and SiO2, has a purity of greater than 99.99% relative to 100% purity measured using the ICP-MS method. Purity.

Embodiment 10. The ceramic sintered body according to any one of the preceding embodiments 1 to 9, wherein the ceramic sintered body has a total impurity content of less than 100 ppm.

Embodiment 11. The ceramic sintered body of any one of the preceding embodiments 1 to 10, wherein the at least one crystal phase includes a cubic solid solution selected from the group consisting of fluorite, c-cube, and combinations thereof.

Embodiment 12. The ceramic sintered body of any one of the preceding embodiments 1 to 11, having a pore diameter measured across a polished surface of no less than 0.1 to no more than 5 μm.

Embodiment 13. The ceramic sintered body of any one of the preceding embodiments 1 to 12, having a pore diameter measured across the polished surface of no less than 0.1 to no more than 3 μm.

Embodiment 14. The ceramic sintered body of any one of the preceding embodiments 1 to 13, having at least one surface with an average particle diameter measured according to ASTM E112-2010 of 0.75 μm to 6 μm.

Embodiment 15. The ceramic sintered body according to any one of the preceding embodiments 1 to 14, which contains a c-type cubic solid solution phase.

Embodiment 16. The ceramic sintered body of any one of the aforementioned embodiments 1 to 15, which has a diameter of 100 to 622mm, preferably 100 to 575mm, preferably 100 to 406mm, preferably 150 to 622mm, preferably Maximum dimensions of 150 to 575 mm, preferably 150 to 406 mm, preferably 406 to 622 mm, and more preferably 406 to 575 mm, each relative to the longest extension of the sintered body.

Embodiment 17. The ceramic sintered body of any one of the preceding embodiments 1 to 16, wherein the ceramic sintered system is selected from the group consisting of: windows in plasma processing chambers, RF windows, lids, focusing rings, shielding rings, nozzles, gas injectors, showerheads, gas distribution plates, chamber liners, chucks, electrostatic chucks, positioning disks, and/or cover rings.

Embodiment 18. A method of manufacturing a ceramic sintered body, the method comprising the following steps: combining powders of yttria and zirconium oxide to form a powder mixture; increasing the temperature of the powder mixture to a calcination by applying heat temperature to calcine the powder mixture and maintain the calcining temperature to form a calcined powder mixture; dispose the calcined powder mixture within a volume defined by the tool set of the sintering equipment and create vacuum conditions within the volume; upon heating While reaching a sintering temperature, pressure is applied to the calcined powder mixture and sintering is performed to form the ceramic sintered body; and the temperature of the ceramic sintered body is reduced.

Embodiment 19. The method of Embodiment 18, further comprising the steps of: optionally annealing the ceramic sintered body by applying heat to increase the temperature of the ceramic sintered body to reach an annealing temperature to form the ceramic sintered body. Annealing the ceramic sintered body; and reducing the temperature of the annealed ceramic sintered body.

Embodiment 20. The method of any one of embodiments 18 to 19, further comprising the step of optionally machining the ceramic sintered body to form ceramic sintered body components in a plasma processing chamber, such as windows, RF Windows, covers, focus rings, shielding rings, nozzles, gas injectors, shower heads, gas distribution plates, chamber liners, chucks, electrostatic chucks, positioning disks, and/or cover rings.

Embodiment 21. The method of any one of embodiments 18 to 20, wherein the calcined powder mixture has a purity of 99.99% or higher relative to 100% purity as measured using an ICP-MS method.

Embodiment 22. The method of any one of embodiments 18 to 21, wherein the calcined powder mixture has 2 to 14 m2/g, preferably 2 to 12 ^m2 /g, preferably 2, measured according to ASTM C1274 to 10m2/g, preferably 2 to 8m2/g, preferably 2 to 6m2/g, preferably 2.5 to 10m2/g, preferably 3 to 10m2/g, preferably 4 to 10m2/g, And more preferably a specific surface area (SSA) of 2 to 5 m2/g.

Embodiment 23. The method of any one of embodiments 18 to 22, wherein the calcination temperature is 600°C to 1200°C.

Embodiment 24. The method of any one of embodiments 18 to 23, wherein the pressure is 10 to 60 MPa.

Embodiment 25. The method of any one of embodiments 18 to 24, wherein the pressure is 10 to 50 MPa.

Embodiment 26. The method of any one of embodiments 18 to 25, wherein the pressure is 10 to 40 MPa.

Embodiment 27. The method of any one of embodiments 18 to 26, wherein the pressure is 10 to 30 MPa.

Embodiment 28. The method of any one of embodiments 18 to 27, wherein the pressure is 15 to 40 MPa.

Embodiment 29. The method of any one of embodiments 18 to 28, wherein the pressure is 15 to 30 MPa.

Embodiment 30. The method of any one of embodiments 18 to 29, wherein the pressure is 15 to 25 MPa.

Embodiment 31. The method of any one of embodiments 18 to 30, wherein the sintering temperature is 1200°C to 1700°C.

Embodiment 32. The method of any one of embodiments 18 to 31, wherein the annealing temperature is 800°C to 1500°C.

Embodiment 33. A ceramic sintered body according to any one of embodiments 1 to 17, which is produced according to the method according to any one of embodiments 18 to 32.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are not restrictive of the disclosure.

50:wafer

9500: Semiconductor processing system; processing system

9502: Plasma source

9506: Gas distribution system; gas delivery system

9507:Window/cover

9508:Chuck

9509:Positioning plate

9512,9612,9710:Top shielding ring

9514,9614: Covering ring

9550: Vacuum chamber; chamber

9600: Semiconductor processing system; processing system; system

9606:Gas delivery system

9608:Chuck; electrostatic chuck

9609: Positioning plate

9610:shaft

9611:Pedestal

9613:Shielding ring

9650: Vacuum chamber

9700: Nozzle/gas distribution plate

9712:Shielding ring

9714:Nozzle/Central Gas Injector

A: No annealing

B:1100℃

C:1550℃; c-type cubic structure

F: Fluorite structure

The present disclosure is best understood from the following detailed description when read in conjunction with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not drawn to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. The drawings include the following figures: [Figure 1] depicts a phase diagram of yttrium oxide and zirconium oxide in accordance with the present disclosure; [Figures 2a) and 2b)] illustrates an x-ray diffraction pattern of an exemplary calcined powder mixture as disclosed herein. X-ray diffraction results; [Figure 3] and [Figure 4] show exemplary x-ray diffraction results of the yttria-zirconia ceramic sintered body as disclosed herein; [Figure 5] shows the results of the yttria-zirconia ceramic sintered body as disclosed herein; Changes in the x-ray diffraction results of annealed zirconia ceramic sintered bodies; [Fig. 6] illustrates 5000 times exemplary microstructures of yttria-zirconia ceramic sintered bodies under different annealing conditions as disclosed herein; [Fig. 7 ] illustrates a first example of a semiconductor processing chamber; and [FIG. 8] illustrates a second example of a semiconductor processing chamber.

Reference will now be made in detail to specific embodiments. Examples of specific embodiments are illustrated in the accompanying drawings. Although the present disclosure will be described in connection with these specific embodiments, it should be understood that there is no intention to limit the disclosure to these specific embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope defined by the appended claims. The following description explains many Specific details are provided in order to provide a thorough understanding of the disclosed embodiments. The disclosure may be practiced without some or all of these specific details.

As used herein, the term "zirconia" is understood to mean zirconium oxide, which includes ZrO ₂ . As used herein, the term "alumina" is understood to mean aluminum oxide, which includes Al ₂ O ₃ . As used herein, the term "yttria" is understood to mean yttrium oxide, which contains Y ₂ O ₃ .

As used herein, the terms "semiconductor wafer," "wafer," "substrate," and "wafer substrate" are used interchangeably. Wafers or substrates used in the semiconductor device industry generally have diameters of 200 mm, or 300 mm, 450 mm, and larger, as known in the industry.

As used herein, the term "ceramic sintered body" is synonymous with "sinter", "body", or "sintered body" and refers to a process made by applying pressure. and heat (which produces a one-piece dense sintered ceramic body) to compact the powder to form a one-piece, one-piece sintered ceramic article. The one-piece sintered ceramic body can be machined into a one-piece sintered ceramic component that can be used as a chamber component in plasma processing applications.

As used herein, the term "nanopowder" is intended to encompass those powders with a surface area (SSA) of 20 m ² /g or greater.

As used herein, the term "purity" refers to the absence of various contaminants and/or impurities in: a) the starting materials from which the powder mixture is formed, b) the processed powder mixture, and c ) a sintered ceramic body as disclosed herein. Higher purity, approaching 100%, represents a material that is substantially free of contaminants, dopants, or impurities and contains only the intended material composition of Y, Zr, and O. The difference between impurities and dopants is that dopants are typically added intentionally to the starting powder or powder mix. These compounds are used to achieve certain electrical, mechanical, optical, or other properties in the sintered ceramic body, such as changes in particle size.

As used herein, the term "impurity" refers to the presence in a) the starting materials from which the powder mixture can be formed, b) the processed powder mixture and/or the calcined powder mixture, and c) the sintered ceramic body Those compounds/contaminants, which contain impurities other than the starting materials themselves, include Y, Zr, and O. After processing/combining, or during sintering, impurities may be present in the starting powder material, powder mixture, and/or calcined powder mixture and are reported as ppm, with lower ppm levels corresponding to lower impurity levels. Impurities recorded herein do not include Si in the form of SiO ₂ or Hf in the form of HfO 2 . The yttrium oxide present in the starting zirconium oxide material is present as a stabilizer and is therefore not considered an impurity.

Conversion of purity to impurities can be performed using a conversion rate of 1 wt% equal to 10,000 pm, as is known to those of ordinary skill in the art. All values reported in ppm herein are relative to the total mass of the material being tested, such as the embodiments of powders and/or sintered ceramic bodies disclosed herein.

As used herein, the term "sintering aid" refers to an additive that enhances densification and thereby reduces porosity during the sintering process, such as calcium oxide (calcia), silica (silica), or magnesium oxide .

As used herein, the term "ceramic sintered body component" refers to a ceramic sintered body after machining steps to produce the specific form required for use in semiconductor manufacturing in a plasma processing chamber or shape.

As used herein, the term "powder mixture" means that the process is preceded by ball milling, jet milling, tumble mixing, drying, calcination, At least one powder is mixed by methods known to those skilled in the art through sieving, purification, and repetition or combination of these steps, which are formed into the disclosed ceramic sintered body and/or after sintering the powder mixture. or ceramic sintered body components.

As used herein, the term "tool set" may include at least one mold and two punches and optionally additional spacer elements.

The terms "phase" or "crystalline phase" are synonymous and, as used herein, shall be understood to mean the ordered structure that forms the crystal lattice of a material, including stoichiometric or compound phases or solid solution phase. As used herein, "solid solution" is defined as a mixture of different elements that share the same lattice structure. The mixture within the crystal lattice may be substitutable, in which atoms of one starting crystal replace atoms of another, or may be interstitial, in which atoms occupy normally vacant positions in the crystal lattice.

The term "calcination" is understood to mean a heat treatment step, which may be carried out on the powder in air at a temperature lower than the sintering temperature, in order to remove moisture and/or impurities, increase crystallinity and in some cases change Surface area of powders and/or powder mixtures.

When applied to the heat treatment of ceramics, the term "annealing" is understood herein to mean bringing the disclosed ceramic sintered body or ceramic sintered body assembly to a temperature and allowing slow cooling to relieve stress and/or to Stoichiometric normalization of heat treatments. Generally speaking, an environment containing air or oxygen can be used.

As used herein, the term "about" when used in conjunction with numbers allows for a variation of plus or minus 10%. As used in this document, the term "substantially" is a descriptive term which indicates an approximation and means "considerable in extent" or "largely but not wholly that which is specified" and is intended to avoid setting strict numerical boundaries on specified parameters.

The following detailed description assumes embodiments implemented within equipment required as part of fabricating semiconductor wafer substrates, such as an etch chamber or a deposition chamber. However, the disclosure is not limited thereto. Workpieces can come in a variety of shapes, sizes, and materials. In addition to semiconductor wafer processing, other workpieces in which embodiments disclosed herein may be utilized include various items such as fine feature size inorganic circuit boards, magnetic recording media, magnetic recording sensors, mirrors, optical components, micromechanical devices, and similar.

During semiconductor device processing, corrosion-resistant components or chamber assemblies are used within plasma processing chambers and are exposed to harsh corrosive environments, which may result in the release of particles into the reactor chamber resulting in wafer-level contamination. resulting in yield loss. The ceramic sintered bodies and related ceramic sintered body components disclosed herein provide improved plasma resistance within semiconductor processing reactor chambers through specific material properties and characteristics described below.

Embodiments disclosed herein provide a ceramic sintered body comprising no less than 75 mole % and no more than 95 mole % yttrium oxide, and no less than 5 mole % and no more than 25 mole % zirconia, wherein The ceramic sintered body contains an amount of porosity less than 2% by volume and has a particle size of 0.5 to 8um as measured according to ASTM E112-2010. The ceramic sintered body has at least one surface that includes at least one crystalline phase including yttria and zirconium oxide, and the surface has a porosity of less than 2% based on pore area and a particle size of 0.5 to 8um. The porosity measured on the polished surface may extend throughout the bulk of the ceramic sintered body, and therefore, the porosity on the polished surface represents volume porosity or bulk porosity. The ceramic sintered bodies disclosed herein may have a density of 98% or higher relative to the theoretical density as defined herein. Ceramic sintered bodies can be made from high-purity yttria and zirconium oxide powders with particle size distribution and surface area that provide handleability, flowability, and chemical reactivity.

Figure 1 depicts a yttria/zirconia phase diagram showing the phases of yttria and zirconia, and the molar combinations that achieve these phases. The formation of the crystalline phase as depicted can be achieved by several parameters such as the molar ratio of the starting powder mixture, the degree of mixing, and the purity of the starting powder. The sintering conditions (such as heating and cooling rate, temperature, and time) and the annealing temperature and time of the disclosed current and pressure-assisted processes can also affect the formation of the crystal phase. As evidenced by the yttria-zirconia phase diagram of Andrievskaya et al. (2014) depicted in Figure 1, guidance for achieving these crystallographic phases of yttria-zirconia is as known to those of ordinary skill in the art. , the entire text of which is incorporated herein by reference.

In an embodiment, this article discloses a yttria-zirconia ceramic sintered body, the yttria-zirconia ceramic sintered body includes a c-type cubic structure (represented as C according to the phase diagram of Figure 1), a fluorite structure (according to the phase diagram of Figure 1 The phase diagram of 1 represents solid solutions of F), and their combinations, as depicted within the square area defined in Figure 1. Within this composition range (horizontal axis) and sintering temperature range (vertical axis), embodiments of ceramic sintered bodies can be formed. In other embodiments (depending on the composition according to the phase diagram of Figure 1) the ceramic sintered body comprises a solid solution having a c-type (yttrium oxide) cubic structure. The c-type yttrium oxide/rare earth oxide crystal structure is revealed in detail according to the following literature: "Phase Equilibria in Systems Involving the Rare-Earth Oxides.Part 1. Polymorphism of the Oxides of the Trivalent Rare-Earth Ions" (R.S. Roth et al., 1960), the entire text of which is incorporated herein by reference.

Ceramic sintered components as disclosed herein may benefit from the use of yttria-zirconia ceramic sintered bodies for several reasons. Compared to other ceramic materials, yttrium oxide has a composition range of not less than 75 mol% to not more than 95 mol% Y ₂ O ₃ and not less than 5 mol% to not more than 25 mol% ZrO ₂ Zirconia ceramic sintered bodies offer an optimal combination of high density (and correspondingly low porosity), halogen-based plasma resistance, dielectric and thermal properties, and hardness. Yttria zirconia ceramic sintered bodies and components made therefrom may be formed from a range of compositions, such as no less than 75 mol% to no more than 95 mol% Y ₂ O ₃ , and no less than 5 mol% to Not more than 25 mol% of ZrO ₂ , preferably not less than 75 mol% to not more than 93 mol% of Y ₂ O ₃ , and not less than 7 mol% to not more than 25 mol% of ZrO ₂ , Preferably it is no less than 75 mol% to no more than 90 mol% of Y ₂ O ₃ , and no less than 10 mol% to no more than 25 mol% of ZrO ₂ , preferably no less than 75 mol% to no more than 25 mol% of ZrO 2 . Not more than 87 mol% Y ₂ O ₃ , and not less than 13 mol% to not more than 25 mol% ZrO ₂ , preferably not less than 75 mol% to not more than 85 mol% Y ₂ O _3. And not less than 15 mol% to not more than 25 mol% of ZrO ₂ , preferably not less than 75 mol% to not more than 83 mol% of Y ₂ O ₃ , and not less than 17 mol% to Not more than 25 mol% ZrO ₂ , preferably not less than 77 mol% to not more than 83 mol% Y ₂ O ₃ , and not less than 17 mol% to not more than 23 mol% ZrO ₂ , Preferably, it is not less than 78 mol% and not more than 82 mol% of Y ₂ O ₃ , and not less than 18 mol% and not more than 22 mol% of ZrO ₂ , and more preferably, about 80 mol% of Y 2 O 3 Y ₂ O ₃ to about 20 mole % ZrO ₂ .

In some embodiments, a c-type cubic phase may be preferred and is formed according to the phase diagram of Figure 1 from a composition including: no less than about 80 mole % to no more than 95 mole % yttrium oxide, and Not less than 5 mol% to not more than 20 mol% of zirconia, preferably not less than 81 mol% to not more than 95 mol% of Y ₂ O ₃ , and not less than 5 mol% to not more than 19 mol% Mol% of ZrO ₂ , preferably no less than 82 mol% to no more than 95 mol% of Y ₂ O ₃ , and no less than 5 mol% to no more than 18 mol% of ZrO ₂ , preferably Not less than 83 mol% to not more than 95 mol% of Y ₂ O ₃ , and not less than 5 mol% to not more than 17 mol% of ZrO ₂ , preferably not less than 84 mol% to not more than 95 mol% Mol% of Y ₂ O ₃ , and not less than 5 mol% to not more than 16 mol% of ZrO ₂ , preferably not less than 86 mol% to not more than 95 mol% of Y ₂ O ₃ , and Not less than 5 mol% to not more than 14 mol% of ZrO ₂ , preferably not less than 88 mol% to not more than 95 mol% of Y ₂ O ₃ , and not less than 5 mol% to not more than 12 mol% Mol% of ZrO ₂ , preferably no less than 90 mol% to no more than 95 mol% of Y ₂ O ₃ , and no less than 5 mol% to no more than 10 mol% of ZrO ₂ , and preferably Ground is not less than 92 mol% to not more than 95 mol% of Y ₂ O ₃ , and not less than 5 mol% to not more than 8 mol% of ZrO ₂ .

Use of ceramic sintered bodies and components prepared according to the methods disclosed herein in semiconductor processing chambers provides enhanced corrosion resistance and erosion resistance to halogen-based process gases. This enhanced plasma resistance results, at least in part, from the high density and correspondingly low porosity of the sintered body. Embodiments of the disclosed yttria-zirconia ceramic sintered bodies (and components made therefrom) may have an Archimedean density of 5.01 to 5.15 g/cc, preferably according to ASTM B962-17 5.01 to 5.13g/cc, preferably 5.03 to 5.13g/cc, preferably 5.06 to 5.13g/cc, preferably 5.08 to 5.15g/cc, preferably 5.08 to 5.13g/cc, preferably 5.10 to 5.13g/cc, preferably 5.12 to 5.13g/cc, preferably 5.01 to 5.11g/cc, preferably 5.01 to 5.10g/cc, preferably 5.06 to 5.15g/cc, preferably The density is preferably 5.06 to 5.12g/cc, and more preferably 5.08 to 5.13g/cc. Table 1 lists the preparation conditions (temperature, time, pressure, and annealing), density, and volume porosity of the yttria zirconia ceramic sintered body disclosed herein.

Volumetric mixing rules as known to those of ordinary skill in the art may not be applicable to solid solutions such as the disclosed ceramic sintered bodies, and therefore may be used to approximate the theoretical densities of the ceramic sintered bodies disclosed herein. The theoretical densities used in this article were estimated using a combination of the volumetric mixing rules disclosed in "an exact density formula for substitutional solid solution alloys" and calculations based on Equation 4 for substituted solid solutions, J. Mater. Sci. Letters 13 (1994), Chen and Bandeira (adapted for calculation of oxide solid solutions of yttria and zirconium oxide). Within the composition range spanning 95 mol% yttria and 5 mol% zirconia, and 75 mol% yttria and 25 mol% zirconia, approximately 5.09 g/cc and 5.15 were calculated, respectively. The theoretical density value of g/cc. Density measurements were performed on the exemplary 80 mole % yttrium oxide and 20 mole % zirconia ceramic sintered bodies disclosed in Table 1 using the Archimedean method according to ASTM B962-17. Commercial grade zirconia systems used herein are known to have up to and including 5 weight percent _HfO2 , which may result in a slight increase in density. Take the average of 5 measurements and measure the highest value to be 5.13g/cc. This value is in good agreement with the calculated value, and therefore, this value is taken as the theoretical density of the ceramic sintered body of 80 mol% yttrium oxide and 20 mol% zirconia. Sample 8 of Table 1 corresponds to an yttria-zirconia ceramic sintered body containing 90 mol% of yttria and 10 mol% of zirconia, and has a density of 5.08 g/cc, which is taken as the composition. theoretical density. N/A indicates that the sample was not annealed.

The relative density (RD) of a given material is defined as the ratio of the measured density of a sample (ρ sample) to the recorded theoretical density (ρ theory) of the same material, as shown in the following equation:

Where p sample is the measured (Archimedean) density according to ASTM B962-17, p theory is the measured theoretical density as disclosed herein, and RD is the relative fractional density. Yttria-zirconia ceramic sintered bodies with high density therefore have correspondingly low porosity. Porosity (which is used synonymously with volumetric porosity herein) can be calculated by subtracting the density of the fully dense fraction (i.e., 100%) from the relative density (calculated above). Using this calculation, the following porosity (or volumetric porosity, as appropriate) as a percentage of the total volume was calculated from the measured Archimedean density values of the yttria-zirconia ceramic sintered bodies disclosed herein: Not Less than 0.05 to no more than 2%, preferably no less than 0.05 to no more than 1.5%, preferably no less than 0.05 to no more than 1%, preferably no less than 0.05 to no more than 0.5%, preferably no less than 0.1 to no more than 1.5%, preferably no less than 0.1 to no more than 1%, preferably no less than 0.1 to no more than 0.5%, and more preferably no less than 0.05 to no more than 0.2%.

The ceramic sintered bodies disclosed herein and related components made therefrom may have a density relative to a theoretical density (or relative density, RD), which is 98 times the theoretical density calculated from density measurements performed in accordance with ASTM B962-17 To 100%, preferably 98.5 to 100%, preferably 99 to 100%, preferably 99.5 to 100%, more preferably 99.8 to 100%. The density variation (relative to the theoretical density) across the largest dimension of the ceramic sintered body (in the case of a disk-shaped sample, the largest dimension is the diameter) may be no greater than 2%, preferably no greater than 1.5%, preferably no greater than 1 %, and preferably no more than 0.8%.

The high density disclosed herein contributes to the high hardness values of the yttria-zirconia sintered ceramic bodies. According to ASTM standard C1327, a 0.1kgf load cell is used for hardness measurement. Table 2 below sets forth the hardness results across approximately 40 total measurements for Samples 1, 2, and 11, each containing approximately 80 mole % yttrium oxide and approximately 20 mole % zirconia. Sample 11 was prepared under similar pressure, temperature, and time conditions as Sample 7.

Embodiments of the yttria-zirconia sintered ceramic body may have a hardness of no less than 8.5 to 14.5 GPa. Other embodiments may have an average hardness of no less than 9.4 to no more than 12.4 GPa, preferably no less than 9.8 to no more than 11.7 GPa, and preferably no less than 10.2 to no more than 11 GPa.

The yttria-zirconia sintered ceramic body may comprise a monolithic body made according to the procedures disclosed herein, and thus may comprise porosity evenly distributed on the surface and throughout the body. In other words, porosity measured on a surface represents the porosity within the volume of the bulk sintered ceramic body, and the terms "porosity" and "volumetric porosity" are therefore considered to have the same meaning as used herein. Same meaning.

Semiconductor processing reactors associated with etching or deposition processes require chamber components made of materials that are highly resistant to chemical attack caused by the reactive plasma necessary for semiconductor processing. These plasma or process gases may contain various halogen, oxygen, and nitrogen-based chemicals, such as O2 _, F, _Cl2 , HBr, _BCl3 , _CCl4 , _N2 , _NF3 , NO, _N2O , C ₂ H ₄ , CF ₄ , SF ₆ , C ₄ F ₈ , CHF ₃ , CH ₂ F ₂ . The use of ceramic sintered bodies formed from corrosion-resistant materials as disclosed herein provides reduced chemical corrosion during use. Additionally, providing chamber component materials with very high purity, such as ceramic sintered bodies, provides a uniform corrosion-resistant body with low impurity content, which can serve as an initiation site for corrosion. In addition, components made from highly dense materials with small diameter minimal pores provide greater resistance to corrosion and erosion during etching and deposition processes. Therefore, preferred chamber components may be those made from materials that are highly resistant to erosion and corrosion during plasma etching and deposition. As used herein, the term "plasma resistance" refers to a material that will not corrode or erode during exposure to halogen-based process gas plasma. This plasma resistance prevents particles from being released from component surfaces into the reactor chamber during semiconductor processing. This release of particles into the reactor chamber results in wafer contamination and semiconductor device-level yield losses caused by drift introduced into the semiconductor process.

Chamber components must have sufficient flexural or mechanical strength to allow for component installation, removal, cleaning, and handleability during use within the process chamber. The use of current and pressure-assisted sintering technology with high heating and cooling rates and short sintering times provides high density and fine particle size in ceramic sintered bodies and related components, thereby providing increased mechanical strength. High mechanical strength allows complex features of fine geometries to be machined into ceramic sintered bodies without cracking, cracking, or chipping. Flexural strength or stiffness becomes particularly important when using large components in state-of-the-art process tools. In some component applications, such as chamber windows with diameters of approximately 200 to 622 mm, significant stresses are exerted on the windows during use under vacuum conditions. This requirement requires the use of corrosion-resistant materials with high strength and stiffness (also known as Young's modulus). Ceramic sintered bodies according to embodiments disclosed herein meet these strength and handleability requirements.

As semiconductor device geometries continue to shrink, temperature control becomes increasingly important in order to minimize process yield losses. Such temperature changes within the processing chamber affect control of the critical dimensions of nanoscale features, thereby adversely affecting device yield. It is desirable to have low dielectric losses, such as, for example, 1×10 ^-4 or less (herein, dielectric loss is related to the terms "dissipation factor" and "loss tangent" (Used synonymously), the materials of the chamber components are selected to prevent the generation of heat that would lead to uneven temperatures within the chamber. Dielectric losses may be affected by, among other factors, particle size, purity, and the use of dopants and/or sintering aids in the material. Combining the use of sintering aids and/or dopants with extended sintering conditions may result in larger particle size, lower purity materials that may not be suitable for use in the high frequency chamber processes common in this industry. A low loss tangent is required and may result in particle generation and reduced mechanical strength, thereby hindering the manufacture of large-size components. Therefore, a ceramic sintered body containing no or substantially no dopants and/or sintering aids is disclosed herein. Preferred for semiconductor chamber components are those materials with the lowest possible dielectric losses in order to increase plasma generation efficiency and prevent overheating, especially in the 1 MHz to 20 GHz (or more) range used in plasma processing chambers. up to RF range) at high frequencies. The heat generated by absorption of microwave energy in component materials with higher dielectric losses leads to uneven heating and increased thermal stress on the components. Table 3 below sets forth the dielectric loss and dielectric constant measured according to ASTM D-150 at ambient temperature, 1 MHz from Samples 9 and 10, which contain approximately 80 moles made according to the methods disclosed herein. % of yttrium oxide and approximately 20 mol% of zirconia. Within the range of measurements performed, the same dielectric performance was measured for annealed yttria-zirconia ceramic sintered bodies and for those without annealing.

Embodiments of ceramic sintered bodies including compositions of yttrium oxide and zirconium oxide may have low levels of porosity, accounting for less than 2%, preferably less than 1%, preferably 0.05% to 0.05% of the total area containing porosity. 2%, preferably 0.05% to 1%, more preferably 0.05% to 0.5%, which can provide improved performance in semiconductor plasma etching and deposition applications. This can lead to extended component life and greater process stability performance, and reduced chamber downtime for cleaning and maintenance. Porosity was measured by image analysis of polished surfaces polished according to the following methods (Strasbaugh polishing equipment, polishing supplies from Struers, Inc.): (i) 40um alumina: as needed to flatten the surface; (ii) )12um alumina fixed abrasive pad: 2min; (iii) 9pm diamond polyurethane pad: 8min; (iv) 6um diamond flannel: 3min, and (v) 1um diamond flannel: 3min. Images were captured using a Nanoscience Instruments Phenom XL scanning electron microscope (SEM) at 5000x magnification. The SEM images were imported into ImageJ image processing software and used to measure and quantify pore diameter and pore area. This article discloses a nearly dense or completely dense yttria-zirconia ceramic sintered body with minimal (<2 vol. %) porosity. This minimal porosity reduces particle generation by providing a highly dense plasma-facing surface, thereby preventing contaminant entrapment in the surface of the ceramic sintered body during etching and deposition processes. The corrosion-resistant ceramic sintered body disclosed herein can have a very high density of greater than 98%, preferably greater than 99%, preferably greater than 99.5%, more preferably about 99.8% relative to the theoretical density, and during ceramic sintering The body has a low porosity correspondingly less than 2%, preferably less than 1%, preferably less than 0.5%, preferably less than 0.2% on the surface and the entire volume, thereby by including the porosity Controlled surface area to provide improved etch resistance. The ceramic sintered system disclosed herein is a monolithic homogeneous body that contains crystalline phase, purity, and porosity/pores both on the surface and in its entirety. Accordingly, characteristics such as crystalline phase, pore size, porosity %, and pore area measured on a surface represent characteristics within the bulk, and thus the volume, of the sintered ceramic body. The term "homogeneous" means that a material or system has substantially the same properties at every point; it is uniform without irregularities. Therefore, "homogeneous body" means a sintered ceramic system in which the distribution of characteristics such as porosity %, pore diameter, pore area, and crystal phase is uniform in space without significant gradients, that is, a substantially uniform sintered ceramic system Existing regardless of location within the subject or on the surface.

Ceramic sintered bodies containing yttria and zirconia are probably among the most etch-resistant materials known, and high purity starting materials are used as starting materials to create very high purity and density ceramic sintered bodies to provide electrical resistance in ceramic sintered components. Pulp characteristics. The presence of impurities or contaminants can serve as initiation sites for corrosion and/or erosion during plasma processing. This high purity protects the surface of the ceramic sintered body from roughening by halogen-based gas species that might otherwise chemically attack, surface roughen, and etch surfaces made from less pure powders. and other components.

For the above reasons, relative to 100% material purity in the yttrium oxide and zirconium oxide starting materials, a total purity greater than 99.99%, preferably greater than 99.995%, preferably greater than 99.999% is preferred.

The purity of the zirconia starting material may be greater than 99.9%, preferably greater than 99.95%, preferably greater than 99.99%, to provide corrosion resistance and erosion resistance during use under etching and deposition chamber conditions. Commercial grade zirconia systems are known to have up to and including 5 weight percent _HfO2 . Zirconia and hafnium oxide (HfO ₂ ) may react similarly during the formation of the yttria zirconia ceramic sintered bodies disclosed herein, and therefore, the presence of HfO 2 in the ceramic sintered bodies is not considered detrimental to the use of the sintered bodies as electrodes. Chamber components in slurry handling applications. Therefore, HfO2 is not considered an impurity as disclosed herein. Additionally, due to the high cost of zirconia powder, it may be impractical to remove hafnium oxide from zirconia to <5 wt%. Therefore, _HfO2 present in the starting zirconia powder is not considered a contaminant or impurity, and therefore is not considered when recording purity, contaminants, and impurities as disclosed herein. The zirconia starting powder may include at least one selected from the group consisting of unstable zirconia, partially stabilized zirconia, and stable zirconia.

The total purity of the calcined powder mixture disclosed herein can be greater than 99.99%, preferably greater than 99.995%, more preferably about 99.999% or higher, each relative to 100% purity of the calcined powder mixture.

Relative to the 100% purity of the ceramic sintered body, the total purity of the ceramic sintered body disclosed herein can be higher than 99.99%, preferably higher than 99.995%. In embodiments using zirconia media for mixing, the molar ratio of yttria to zirconia can be adjusted to take into account the wear of the media to achieve the final desired composition, and the purity of the ceramic sintered component can be consistent with the ceramic sintered body and The purity of the relevant starting materials remains consistent.

Preparation method

The preparation of ceramic sintered bodies can be accomplished by combining pressure-assisted sintering with direct current sintering and related techniques that employ direct current heating of conductive mold configurations or tool sets to heat the material to be sintered. This heating method allows the application of very high heating and cooling rates, enhances the densification mechanism rather than the grain growth promoting diffusion mechanism, which can promote the preparation of very fine particle size ceramic sintered bodies, and transfer the inherent characteristics of the original powder to in products that are nearly or completely dense.

A ceramic sintered body is prepared by a method that includes the following steps: a. combining powders of yttrium oxide and zirconium oxide to form a powder mixture; b. increasing the temperature of the powder mixture to a calcination temperature to calcine the powder mixture and maintain the calcination temperature to form a calcined powder mixture; c. disposing the calcined powder mixture within a volume defined by the tool set of the sintering equipment and creating a vacuum within the volume Conditions; and d. apply pressure to the calcined powder mixture while heating to a sintering temperature, and perform sintering to form the ceramic sintered body; and e. reduce the temperature of the ceramic sintered body. The following additional method steps are optional: f. Optionally increase the temperature by applying heat annealing the ceramic sintered body by raising the temperature of the ceramic sintered body to reach an annealing temperature to form an annealed ceramic sintered body; and g. lowering the temperature of the annealed ceramic sintered body; and h. mechanically processing the ceramic sintered body. body to form ceramic sintered body components (which may also be annealed in embodiments) in a plasma processing chamber, such as windows, RF windows, covers, focus rings, shielding rings, nozzles, gas injectors, showerheads, gas distribution plates , chamber liners, chucks, positioning disks, and/or cover rings. Embodiments of ceramic sintered body components including windows, RF windows, or covers may be considered equivalents as disclosed herein.

The properties of corrosion-resistant ceramic sintered body components formed from ceramic sintered bodies are specifically achieved by adjusting the purity of the starting powders of yttria and zirconium oxide and the purity of the powder mixture (with yttria and zirconium oxide). ) of the calcined powder mixture, the sintering temperature, the sintering duration, the temperature of the ceramic sintered body/ceramic sintered body component during the optional annealing step, and the duration of the optional annealing step.

The methods disclosed herein provide for the preparation of ceramic sintered bodies and/or ceramic sintered body components across a composition range of no less than 75 mole % to no more than 95 mole % yttrium oxide (Y ₂ O ₃ ), and not less than 5 mol% to not more than 25 mol% zirconium oxide (ZrO ₂ ).

The characteristics of the ceramic sintered body and the ceramic sintered body component according to one embodiment are specifically achieved by: starting powder particle size distribution (PSD), specific surface area (SSA), purity (via inductively coupled mass spectrometry (ICP) -MS), and the method of powder mixing/combination, and the calcined powder mixture, the particle size and surface area of the calcined powder mixture, the pressure on the calcined powder mixture, the sintering temperature of the powder mixture, the sintering duration of the powder mixture time, the temperature of the ceramic sintered body or component during the optional annealing step, and the duration of the optional annealing step. The disclosed procedures provide for the preparation of single phase cubic, c-type yttrium oxide (C), or mixed phase cubic (phases of c-type yttrium oxide and fluorite (F) crystal structures) ceramic sintered bodies containing Features high purity, low volume porosity, and high density Degree of yttrium oxide and zirconium oxide. The ceramic sintered body is particularly suitable for use as a ceramic sintered body or a corrosion-resistant member in plasma processing equipment such as semiconductor manufacturing equipment. Such parts or components may include windows, covers, nozzles, syringes, spray heads, chamber liners, wafer holders, electronic wafer chucks, and various rings known to those of ordinary skill in the art, such as, for example, focus rings and protective ring.

Step a) of the method disclosed herein includes combining powders of yttria and zirconium oxide to form a powder mixture. The starting materials for yttrium oxide and zirconium oxide used to form ceramic sintered bodies and/or components are preferably high purity commercially available powders. However, other oxide powders may be used, such as those produced by chemical synthesis processes and related methods. The zirconia starting powder may include at least one selected from the group consisting of unstable zirconia, partially stabilized zirconia, and stable zirconia. Yttria is known to be added as a stabilizer for zirconia, and therefore, in some embodiments, yttria may be preferred as a stabilizer for zirconia to provide high purity compounds containing Y, Zr, and O as disclosed herein. Ceramic sintered body, but other known zirconia stabilizers can still be used.

In step a), the ceramic powders of yttria and zirconium oxide are processed in batches according to the required molar ratio of yttria and zirconium oxide in the ceramic sintered body. The ceramic sintered body can be made from a molar range of no less than 75 mol% to no more than 95 mol% of yttrium oxide (Y ₂ O ₃ ), and no less than 5 mol% to no more than 25 mol% of zirconium oxide (ZrO). ₂ ) powder mixture is formed. The purity of the yttrium oxide powder can be greater than 99.9%, preferably greater than 99.99%, preferably greater than 99.999%, preferably approximately 99.9999%, and the purity of the zirconia powder can be greater than 99.95%, preferably greater than 99.99%, preferably greater than 99.995%. The reporting limits for detecting the presence of lighter elements (such as from Sc or lighter) using the ICPMS disclosed herein (which are about 1.4 ppm or less) are generally higher than the reporting limits for heavier elements (which can be about 0.14 ppm or lower). Specifically, detection of Si using the ICPMS method disclosed herein can be accomplished within a confidence level of approximately 14 ppm or greater. Accordingly, the starting powder, powder mixture, calcined powder mixture, and sintered ceramic body may contain about 14 ppm or less silica. Si in the form of silica is not included in the % purity or impurity content of the starting powders, calcined powder mixtures, and sintered ceramic bodies disclosed herein, and may be taken to be about 14 ppm or less, but in many In this case Si is not detected.

Table 4 sets forth exemplary 80 mole % yttria/20 mole % zirconia calcined powder mixtures 1 to 7 made from the disclosed mixtures of yttria and zirconia starting materials using ICP-MS Measured impurities/contaminants (in ppm) and % purity (relative to 100% purity) (Hf was not included as an impurity in the results for reasons disclosed herein, and 14 ppm or less could be detected silica, but silica is usually not detected).

Zirconia starting materials generally contain zirconium, HfO2, and impurities. In one embodiment, the starting material may include greater than 94 wt% zirconia, less than 5 wt% HfO2, and less than 0.1 wt% impurities, or greater than 96 wt% zirconia, less than 3 wt% HfO2, and less than 0.05 wt % impurities. Impurities. In a further embodiment, in addition to impurities, the zirconia starting material consists of greater than 94 wt% zirconia and less than 5 wt% HfO2, or greater than 96 wt% zirconia and less than 3 wt% HfO2, wherein the total amount of impurities Less than 0.1wt%, preferably less than 0.05wt%, and more preferably less than 0.02wt%.

Impurities may generally include metallic elements such as Al, B, Ca, Cr, Co, Cu, Fe, Pb, Li, Mg, Mn, Ni, K, Na, Sn, and Zn, as well as respective metal oxides thereof .

Specific surface areas of starting powders, powder mixtures, and calcined powder mixtures were measured using the Horiba BET Surface Area Analyzer model SA-9601, which is capable of measuring specific surface areas spanning 0.01 to 2000 m ² /g and for large The accuracy of most samples is 10% or less. The particle size of the starting powder, powder mixture, and calcined powder mixture was measured using a Horiba model LA-960 laser scattering particle size distribution analyzer capable of measuring particle sizes from 10 nm to 5 mm. As used herein, d50 is defined as the median and represents the value at which half of the particle size distribution lies above and the other half lies below it. Similarly, 90 percent of the distribution lies below d90, and 10 percent of the distribution lies below d10.

The surface area of yttrium oxide powder can generally range from 1 to 15 m ² /g, preferably from 2 to 10 m ² /g, preferably from 2 to 8 m ² /g, preferably from 2 to 6 m ² /g, preferably from 3 to 3 m 2 /g. 10m ² /g, preferably 4 to 10m ² /g, preferably 6 to 10m ² /g, preferably 2 to 4m ² /g.

According to the embodiments disclosed herein, the d10 particle size of the yttrium oxide powder used as the starting material is preferably 1 to 6 μm, preferably 1 to 5 μm, preferably 1 to 4 μm, preferably 2 to 6 μm, Preferably 3 to 6 μm, preferably 4 to 6 μm, preferably 2 to 4 μm.

According to the embodiments disclosed herein, the d50 particle size of the yttrium oxide powder used as the starting material is preferably 3 to 9 μm, preferably 3 to 8.5 μm, preferably 3 to 8 μm, and preferably 3 to 7 μm. , preferably 4 to 9 μm, preferably 5 to 9 μm, preferably 6 to 9 μm, preferably 4 to 8 μm. The yttrium oxide powder disclosed herein may have an average particle size of about 5 to 9 μm.

According to the embodiments disclosed herein, the d90 particle size of the yttrium oxide powder used as the starting material is preferably 6 to 16 μm, preferably 6 to 15 μm, preferably 6 to 14 μm, preferably 6.5 to 16 μm, Preferably 7 to 16 μm, preferably 7.5 to 16 μm, preferably 7.5 to 14 μm.

The purity of the yttrium oxide starting material is preferably greater than 99.99%, preferably greater than 99.995%, preferably greater than 99.999%, more preferably greater than 99.9995%, and more preferably about 99.9999%. This corresponds to 100 ppm or less, preferably 50 ppm or less, preferably 25 ppm or less, preferably 10 ppm or less, preferably about 1 ppm, preferably 1 to 100 ppm, preferably 1 to Impurity levels of 50 ppm, preferably 1 to 25 ppm, preferably 1 to 10 ppm, preferably 1 to 5 ppm.

Zirconia as used herein generally contains Hf in the form of HfO2 in an amount of about 2 to 5 mole % and up to 5 weight %, which is common in many commercially available zirconia powders. Because of its chemical properties similar to zirconia, Hf is not considered an impurity disclosed herein and is therefore not included in the purity/impurity quantities. Zirconia powder generally has a specific surface area of 1 to 16 m ² /g, preferably 2 to 12 m ² /g, and more preferably 4 to 9 m ² /g. Relative to 100% purity, the purity of the zirconia starting powder is generally higher than 99.5%, preferably higher than 99.8%, preferably higher than 99.9%, preferably higher than 99.99%, more preferably higher than 99.995% . This corresponds to a total impurity content of 5000 ppm or less, preferably 2000 ppm or less, preferably 1000 ppm or less, preferably 100 ppm or less, and better still 50 ppm or less.

The zirconia powder may have a particle size distribution of d10 from 0.08 to 0.50um, d50 from 0.5um to 0.9um, and d90 from 0.9 to 5μm.

The starting powders with zirconium oxide and yttria disclosed herein are preferably crystalline and therefore have long-range crystallization order. Starting powders with high surface areas, such as those in excess of 20 m ² /g, pose handleability problems. Therefore, it is preferred that the powder mixture and/or the calcined powder mixture disclosed herein contains no or substantially no nanopowders and has a specific surface area (SSA) of about 18 m ² /g or less.

Starting powders with a specific surface area less than about 1 m ² /g may suffer from cohesion problems, require higher mixing energy and longer mixing times, and may reduce the sintering activation energy, resulting in lower density and higher porosity. Ceramic sintered body. Preferred for use in the disclosed methods are starting powders disclosed herein that generally have 1 to 18 m ² /g, preferably 2 to 15 m ² /g of SSA.

According to step a), wet or dry ball (axial rotation) grinding, wet or dry tumble (upright or vertical) mixing, jet grinding, and combinations thereof known to those skilled in the art can be used The powder preparation technology is used to combine the selected ceramic powders with yttrium oxide and zirconium oxide. The use of these powder combination methods provides a high-energy process that breaks down particles and agglomerates.

The starting powder can be ball milled or end-over-end/tumble mixed under dry conditions using high purity (>99.9%) alumina media. In other embodiments, zirconia media can be used to break down hard agglomerates. As an example, ball milling may be achieved using zirconia media and performed according to methods known to those of ordinary skill in the art. In embodiments using zirconia media for mixing, the molar ratio of yttria to zirconia can be adjusted to take into account the wear of the media, thereby achieving the final desired composition, and the purity of the ceramic sintered component can be very close to the ceramic sintered body The purity of the ceramic sintered body and related starting materials may be consistent with the purity of the ceramic sintered body and related starting materials. In other cases, aluminum oxide media may be used. In embodiments where an alumina medium is used for mixing, alumina may be present in trace amounts in the ceramic sintered body. The media used to perform dry ball milling can have a range of sizes, such as 5 to 15 mm in diameter, and is added at a loading of about 50 to about 100% of the powder weight. The media used for dry tumbling mixing may include, but is not limited to, at least one large-sized media element (approximately 20 to 40 mm in diameter). Dry ball milling and/or dry tumbling mixing can be carried out for 12 to 48 hours, preferably 16 to Duration of 48 hours, preferably 16 to 24 hours, preferably 18 to 22 hours. Dry ball milling or tumble grinding process (axial rotation) can use RPM of 50 to 250 RPM, preferably 75 to 200 RPM, preferably 75 to 150 RPM, preferably 100 to 125 RPM, each for a container with a diameter of about 200 mm. The RPM may vary depending on the container size chosen for use, and therefore, as is known to those of ordinary skill in the art, containers with diameters greater than 200 mm may have correspondingly lower RPMs. Dry stand/tumble mixing can be performed at an RPM of 10 to 30 rpm, preferably about 20 RPM. After dry ball milling and/or vertical/tumble grinding/mixing, the powder mixture may optionally be sieved using any number of sieves (which may have openings of, for example, 45 to 400um) and blended, but for those skilled in the art There are no limitations on repetition or sequence known to a person of ordinary skill in the art.

The slurry can be formed by wet ball milling or wet stand/tumble mixing by suspending the starting powder in various solvents such as ethanol, methanol, and other alcohols. The slurry formed in either process may have a powder loading of 25 to 75 wt% powder, preferably 40 to 75 wt% powder, preferably 50 to 75 wt% powder during grinding or mixing. Wet ball milling or wet stand/tumble mixing can provide improved powder dispersion through increased flowability, resulting in fine scale, uniform mixing prior to heat treatment or calcination. In other embodiments, 25 to 50% by weight of the powder may be used for wet mixing, such as water, ethanol, isopropyl alcohol, and 25 to 150% by weight of the powder may be added to the powder mixture to form a slurry. material. The wet grinding process can be performed with the same duration and RPM disclosed for the dry process.

As is known to those of ordinary skill in the art, in the case of using a wet mixing or grinding process, the slurry can be dried by a rotary evaporation method depending on the volume of the slurry to be dried, for example at about 40° C. to 1 to 4 hours at 90°C. In other embodiments, the slurry may be dried using spray drying techniques as known to those of ordinary skill in the art. After drying, powder The final mixture may optionally be sieved using a sieve with an opening of, for example, 45 to 400 m, and blended, but there is no restriction on the repetition or sequence. The aforementioned powder preparation techniques can be used alone or in any combination thereof.

After drying, the powder mixture of step a) may have a density of 2 to 18 m ² /g, preferably 2 to 17 m 2 /g, preferably 2 to 14 m ² /g, preferably 2 to 12 m ² /g, preferably 2 to 10m ² /g, preferably 4 to 17m ² /g, preferably 6 to 17m ² /g, preferably 8 to 17m ² /g, preferably 10 to 17m ² /g, preferably Specific surface area (SSA) of 4 to 12 m ² /g, preferably 4 to 10 m ² /g, and preferably 5 to 8 m ² /g.

After mixing/milling, the purity of the powder mixture can be kept consistent with the purity of the starting materials by using high-purity grinding media (such as alumina media with a purity of 99.99% or higher).

Additional powder preparation procedures with attrition milling, high shear mixing, planetary milling, and other known procedures may also be applied. The aforementioned powder preparation techniques can be used alone or in any combination thereof, or with more than one powder mixture that is subsequently combined into a final ceramic sintered body.

Step b) of the methods disclosed herein includes calcining the powder mixture by applying heat to increase the temperature of the powder mixture to a calcining temperature, and maintaining the calcining temperature to perform calcining to form a calcined powder mixture. This step can be performed so that moisture is removed before sintering and the surface condition of the powder mixture is uniform and homogeneous. The calcination according to the heat treatment step may be at 600°C to 1200°C, preferably 600 to 1100°C, preferably 600 to 1000°C, preferably 600 to 900°C, preferably 700 to 1100°C, preferably 800 to 800°C. It is carried out at a temperature of 1100°C, preferably 800 to 1000°C, and preferably 850 to 950°C. Calcination may be carried out in an oxygen-containing environment for a duration of 4 to 12 hours, preferably 4 to 10 hours, preferably 4 to 8 hours, preferably 6 to 12 hours, preferably 4 to 6 hours. After calcination, the powder mixture can be sieved and/or tumbled and/or blended according to known methods to At least a first calcined powder mixture and a second calcined powder mixture are formed. Calcination may or may not result in a reduction in specific surface area.

The calcined powder mixture typically has a d10 particle size of 0.1 to 4um, a d50 particle size of 4 to 8um, and a d90 particle size of 8 to 12um.

The calcined powder mixture typically has a thickness of 2 to 14 m2/g, preferably 2 to 12 ^m2 /g, preferably 2 to 10 m2/g, preferably 2 to 8 m2/g, preferably 2, as measured according to ASTM C1274 Specific surface area (SSA) to 6 m2/g, preferably 2.5 to 10 m2/g, preferably 3 to 10 m2/g, preferably 4 to 10 m2/g, and more preferably 2 to 6 m2/g.

The calcined powder mixture generally has a purity of 99.99% to 99.9995%, preferably 99.9925% to 99.9995%, preferably 99.995% to 99.9995%, preferably 99.995% to 99.999%, as measured using the ICPMS method, each relative to At 100% purity, and having an impurity content (ppm) of 5 ppm to 100 ppm, preferably 75 ppm to 5 ppm, preferably 50 ppm to 5 ppm, preferably 10 ppm to 50 ppm. The impurity levels disclosed herein exclude Hf in the form of _HfO2 and Si in the form of silicon dioxide SiO2. Using the disclosed ICPMS method, approximately 14 ppm or less of silica can be detected. No silica was detected in the calcined powder mixture, and therefore silica may be present in an amount of about 14 ppm or less.

In addition to the aforementioned powder combination process, a jet grinding process known to those skilled in the art may also be used to thoroughly mix the starting powders and/or the calcined powder mixture, thereby providing a powder or powder mixture with a narrow particle size distribution. . Jet milling uses high-velocity jets of inert gas or air to impinge particles of starting powders and/or powder mixtures and/or calcined powder mixtures, but without the use of grinding or mixing media, thereby maintaining the initial purity of the powder to be ground. The chamber can be designed so that larger particles can be preferentially reduced in size, which can be achieved in the final powder, powder mixture, or calcined powder. Provides a narrow particle size distribution in the mixture. Powder leaves the jet grinding chamber when it reaches the desired particle size determined during machine setup prior to processing. The starting powders, powder mixtures, and/or calcined powder mixtures disclosed herein may be subjected to jet milling at a pressure of about 100 psi, either alone or in conjunction with any of the powder grinding/mixing processes disclosed herein. This is true if one or all of them are combined. After jet grinding, the powder and/or powder mixture may optionally be sieved using any number of sieves (which may have, for example, 45 to 400 um openings) and blended, but there is no limit to the repetition or order. Any of the starting powder, powder mixture, and/or calcined powder mixture may optionally be passed through known methods at various process steps using any number of sieves (which may have, for example, 45um to 400um openings) Sieve, blend and/or dry grind, but there is no limit on repetition or order.

Step c) of the method disclosed herein includes disposing the calcined powder mixture within a volume defined by the tool set of the sintering apparatus and creating vacuum conditions within the volume. A sintering apparatus used in a process according to one embodiment includes a tool set that includes at least one graphite mold. The graphite mold is typically a cylindrical graphite mold having a volume, an inner wall, and a first opening and a second opening. The tool set further includes a first punch and a second punch. The first punch and the second punch are operably coupled with the mold, wherein each of the first punch and the second punch has an outer wall defining a diameter smaller than the diameter of the inner wall of the mold such that when the first punch and the second punch are When at least one of the first punch and the second punch moves within the volume of the mold, a gap is generated between each of the first punch and the second punch and the inner wall of the mold. The tool set disclosed herein has a gap of no less than 10 to no more than 100 μm, wherein the gap is configured between the inner wall of the mold and the outer wall of each of the first punch and the second punch, as shown in the U.S. Provisional As disclosed in Patent Application No. 63/124,547, the entire text of which is incorporated herein by reference. SPS equipment and procedures are disclosed, for example, in US Patent Application Publication No. 2010/0156008 A1, which is incorporated herein by reference. The first punch moves in the first opening of the mold and disposes the calcined powder mixture in the second opening of the mold, and the second punch moves in the second opening of the mold to dispose the calcined powder mixture in Within the volume defined by the tool set of the sintering equipment. Vacuum conditions, known to those of ordinary skill in the art, are established within a volume defined by the toolset. Typical vacuum conditions include pressures of 10 ^-2 to 10 ^-3 Torr or less. A vacuum is primarily applied to remove air to protect the graphite from burning and to remove most of the air from the calcined powder mixture. The methods disclosed herein provide a process for producing ceramic sintered bodies and/or sintered ceramic components that is scalable and compatible with commercial manufacturing methods. This method uses powders with micron-level average particle size distribution. These powders are commercially available powders and/or powders prepared by chemical synthesis technology, but do not require sintering aids. The green body is cold-pressed before sintering. Forming, or machining.

The disclosed method utilizes commercially available powders or powders prepared by chemical synthesis technology, but does not require polymerization additives (such as binders or deflocculants), sintering aids, cold pressing and shaping of green bodies before sintering, or machining.

Step d) of the method disclosed herein includes applying pressure to the calcined powder mixture while heating to a sintering temperature and sintering to form a ceramic sintered body, and step e) includes cooling by removing the heat source of the sintering apparatus ceramic sintered body to reduce the temperature of the ceramic sintered body. After placing the calcined powder mixture within the volume defined by the tool set, pressure is applied to the powder mixture. Therefore, the pressure is increased to 5MPa to 60MPa, preferably 5MPa to 40MPa, preferably 5MPa to 30MPa, preferably 5MPa to 20MPa, preferably 5MPa to 10MPa, preferably 10MPa to 60MPa, preferably 10MPa to 40MPa , preferably 10MPa to 30MPa, preferably 10MPa to 20MPa, preferably 15MPa to 60MPa, preferably 15MPa to 40MPa, preferably 15MPa to 30MPa, preferably 15MPa to 25MPa, preferably 15 to 20MPa pressure. Pressure is exerted axially on the calcined powder mixture disposed within a volume defined by the tool set of the sintering apparatus.

In a preferred embodiment, the powder mixture is heated directly through the punches and dies of the sintering equipment. The mold may contain conductive materials that promote resistive/Joule heating, such as graphite. The sintering equipment and procedure are disclosed in US 2010/0156008 A1, which is incorporated herein by reference.

Sintering the calcined powder mixture (including yttria and alumina) under pressure produces a co-compacted one-piece sintered ceramic body. According to the disclosed methods, the calcined powder mixture is sintered in situ to form the sintered ceramic body comprising the yttria and zirconium oxide compositions disclosed herein.

The temperature of sintering equipment according to the present disclosure is typically measured within the graphite mold of the equipment. Therefore, it is preferred that the temperature is measured as close as possible to the calcined powder mixture being processed so that the indicated temperature is exactly achieved within the calcined powder mixture to be sintered.

Applying heat to the powder mixture provided in the mold is preferably about 1200 to about 1700°C, preferably about 1200 to about 1650°C, preferably about 1200 to about 1625°C, preferably about 1300 to about 1700°C, preferably The temperature is about 1400 to about 1700°C, preferably about 1500 to about 1700°C, preferably about 1400 to about 1650°C, preferably about 1500 to 1650°C, preferably about 1550 to 1650°C, and more preferably The sintering temperature is about 1600 to 1650℃.

Sintering generally takes 0.5 to 180 minutes, preferably 0.5 to 120 minutes, preferably 0.5 to 100 minutes, preferably 0.5 to 80 minutes, preferably 0.5 to 60 minutes, preferably 0.5 to 40 minutes, preferably 0.5 to 20 minutes, preferably 5 to 120 minutes, preferably 10 to 120 minutes, preferably 20 to 120 minutes, preferably 40 to 120 minutes, preferably 60 to 120 minutes, preferably 30 This can be achieved with a sintering time of up to 120 minutes, preferably 30 to 90 minutes. In certain embodiments, sintering can be achieved with a sintering time of zero, and upon reaching the sintering temperature, the cooling rates disclosed herein are initiated. In process step e), the sintered ceramic body is passively cooled by removing the heat source. Natural convection can occur until a temperature is reached that facilitates processing of the sintered ceramic body and initiation of the optional annealing process.

During sintering, volume reduction generally occurs such that the ceramic sintered body may comprise approximately one-third of the volume of the starting powder mixture when disposed in the tool set of the sintering apparatus.

In one embodiment, the order in which pressure and temperature are applied may be desired in accordance with the present disclosure, meaning that the indicated pressure may be applied first and then heat is applied to achieve the desired temperature. Additionally, in other embodiments, the indicated heat may be applied first to reach the desired temperature, and then the indicated pressure may be applied. In a third embodiment according to the present disclosure, temperature and pressure may be applied simultaneously or intermittently to the powder mixture to be sintered and increased until reaching the indicated values.

Induction or radiant heating methods can also be used to heat the sintering equipment and indirectly heat the powder mixture in the tool set.

Compared to other sintering techniques, preparation of the sample before sintering (ie by cold pressing or forming a green body (preform) before sintering) is not necessary and the calcined powder mixture is filled directly in the mold. This preparation method will provide high purity in the final ceramic sintered body by avoiding contamination associated with the formation and handling of green bodies, laminates, or tapes prior to sintering that are often associated with other methods.

Further comparing to other sintering technologies, this method does not require sintering aids. For optimal plasma resistance performance, a high purity starting powder is desirable. The lack of sintering aids and the use of high purity starting materials between 99.99% and about 99.9999% purity enables the production of high purity ceramic sintered bodies that provide improved plasma resistance for use as Ceramic sintered components in semiconductor etching and deposition chambers. The ceramic sintered body may have a purity of 99.99% or higher, preferably 99.995% higher, more preferably 99.999%, each relative to 100% purity. These purities reported do not include silicon dioxide in the form of _SiO2 or Hf in the form of _HfO2 . Silicon dioxide (SiO ₂ ) can be measured as low as 14 ppm using the disclosed ICPMS method, and Hafnium oxide (HfO ₂ ) is not detrimental to use within the plasma processing chamber and is therefore not considered an impurity or contaminants.

In one embodiment of the present invention, process step d) may further include a pre-sintering step, wherein at least one heating slope is 0.1°C/min to 100°C/min, 0.1°C/min to 50°C/min, 0.1°C/min to 25℃/min, preferably 0.5℃/min to 50℃/min, preferably 0.5 to 25℃/min, preferably 0.5 to 10℃/min, preferably 0.5℃/min to 5℃/ min, preferably 1 to 10°C/min, preferably 1 to 5°C/min, preferably 2 to 5°C/min, until a specific pre-sintering time is reached.

In a further embodiment of the present invention, the process step d) may further include a pre-sintering step, wherein at least one pressure slope is 0.15 to 30MPa/min, 0.15 to 20MPa/min, 0.15 to 10MPa/min, 0.15 to 5MPa/min. , 0.25 to 20MPa/min, 0.35MPa/min to 20MPa/min, 0.5MPa/min to 20MPa/min, 0.75MPa/min to 20MPa/min, 1MPa/min to 20MPa/min, 5MPa/min to 20MPa/min, Preferably 0.15 to 5MPa/min, preferably 0.15 to 1MPa/min, preferably 0.15 to 0.5MPa/min, until the specific pre-sintering time is reached.

In another embodiment, the process step d) may further include a pre-sintering step with the above-mentioned specific heating slope and with the above-mentioned specific pressure slope.

At the end of process step d), in one embodiment, the method may further comprise step e) reducing the temperature of the ceramic sintered body by cooling the ceramic sintered body by removing the heat source, which can be performed according to those skilled in the art. It is carried out under known vacuum conditions with natural cooling (non-forced cooling) of the process chamber. In a further embodiment according to process step e), the ceramic sintered body can be cooled under convection with an inert gas, for example under 1 bar of argon or nitrogen or any inert gas. Other gas pressures greater or less than 1 bar may also be used. In a further embodiment, the ceramic sintering system is in an oxygen-containing environment. Cooling under forced convection conditions. To initiate the cooling step, at the end of the sintering step d), the power applied to the sintering device is removed and the pressure applied to the ceramic sintered body is removed, followed by cooling according to step e).

Step f) of the methods disclosed herein includes optionally annealing the ceramic sintered body (or in embodiments optionally annealing the sintered ceramic component) by applying heat to increase the temperature of the ceramic sintered body to an annealing temperature ), annealing is performed, and step g) includes lowering the temperature of the annealed ceramic sintered body. In optional step f), the ceramic sintered body or ceramic sintered component obtained in step d) or h) may be subjected to an annealing process (herein, annealing may also be referred to as "thermal oxidation"), and such terms are deemed to have the same meaning). Annealing is typically performed in an oxygen-containing environment such as air or forced convection. In other cases, the ceramic sintered body or component may not be annealed. According to other embodiments, the annealing may be performed while removing the sintering device from an external furnace, or within the sintering device itself without removal.

For the purpose of annealing according to preferred embodiments of the present disclosure, the ceramic sintered body may be removed from the sintering apparatus after cooling according to process step e), and the annealing process step may be performed in a separate apparatus such as a furnace.

In some embodiments, the ceramic sintered body in step d) may subsequently be annealed within the sintering apparatus for purposes of annealing in accordance with the present disclosure, but does not need to self-sinter between sintering step d and optional annealing step f) removed from the device.

This annealing results in a refinement of the chemical and physical properties of the sintered body. The annealing step can be performed by conventional methods for annealing glasses, ceramics, and metals, and the degree of refining can be selected by selecting the annealing temperature and the duration for which annealing is allowed to continue.

In embodiments, the optional step f) of annealing the sintered ceramic body is 0.5°C/min to 20°C/min, preferably 0.5°C/min to 25°C/min, more preferably 0.5°C/min to 10℃/min, and better 0.5℃/min to 5℃/min, preferably 1℃/min to 50℃/min, preferably 3℃/min to 50℃/min, preferably 5℃/min to 50℃/min, More preferably 25℃/min to 50℃/min, preferably 1℃/min to 10℃/min, preferably 2℃/min to 10℃/min, preferably 2℃/min to 5℃/ The heating rate is min.

In embodiments, the optional step f) of annealing the sintered ceramic body is at about 900 to about 1600°C, preferably about 1100 to about 1600°C, preferably about 1300 to about 1600°C, preferably about It is carried out at a temperature of 900 to about 1500°C, preferably about 900 to about 1400°C, preferably about 1400 to about 1600°C.

In embodiments, the optional step f) of annealing the sintered ceramic body is 0.5°C/min to 20°C/min, preferably 0.5°C/min to 25°C/min, more preferably 0.5°C/min to 10℃/min, and more preferably 0.5℃/min to 5℃/min, more preferably 1℃/min to 50℃/min, more preferably 3℃/min to 50℃/min, more preferably 5℃ /min to 50℃/min, preferably 25℃/min to 50℃/min, preferably 1℃/min to 10℃/min, preferably 2℃/min to 10℃/min, preferably The cooling rate is from 2℃/min to 5℃/min.

The optional annealing step f) is intended to improve oxygen vacancies in the crystal structure and return the ceramic sinter to stoichiometric ratios (the disclosed current and pressure-assisted methods produce a generally reduced and oxygen-deficient ceramic sinter). The optional annealing step may be performed at the annealing temperature for 1 to 24 hours, preferably 1 to 18 hours, preferably 1 to 16 hours, preferably 1 to 8 hours, preferably 4 to 24 hours, preferably Duration of 8 to 24 hours, preferably 12 to 24 hours, preferably 4 to 12 hours, and preferably 6 to 10 hours.

Typically, the optional process step f) of annealing the ceramic sintered body is performed in an oxidizing atmosphere, where the annealing process can provide increased albedo and reduced stress, thereby providing opportunities for improvement. Mechanical treatment and reduced porosity. In embodiments, the optional annealing step may be performed in an oxidizing environment such as air or forced convection.

After the optional process step f) of annealing the ceramic sintered body, the temperature of the sintered and in some cases annealed ceramic sintered body is reduced according to process step g) to ambient temperature ("ambient" as used herein meaning a temperature of about 22°C to about 25°C), and the sintered and optionally annealed ceramic body is removed from the furnace (in the case where the annealing step is performed outside the sintering equipment) or removed from the tool set Except (in case the annealing step f is carried out in the sintering equipment).

According to one embodiment, the pressure and current-assisted process described above is suitable for preparing large-scale yttria-zirconia ceramic sintered bodies. The disclosed process provides rapid powder consolidation and densification, maintains a maximum particle size of less than 8um in the sintered ceramic body, and achieves a high density exceeding the theoretical 98% and a volume porosity of less than 2%. High density (>98%) combined with fine particle size (<8um) will improve processability and reduce overall stress in the sintered ceramic body. This combination of fine particle size and high density provides large-sized, high-strength sintered yttria-zirconia ceramic sintered bodies suitable for machining, processing, and use as components in semiconductor processing chambers.

Step h) of the methods disclosed herein includes optionally machining the ceramic sintered body or, in some embodiments, machining the ceramic sintered body after an optional annealing process to form the ceramic in a plasma processing chamber Sintered components such as windows, RF windows, covers, focus rings, shielding rings, nozzles, gas injectors, showerheads, gas distribution plates, chamber liners, electrostatic chucks, positioning plates, and/or cover rings, and can be used depending on the application This is performed by known methods of machining corrosion-resistant ceramic components from the ceramic sintered bodies disclosed herein. Corrosion-resistant ceramic sintered components required for semiconductor etching and deposition chambers may include RF or dielectric windows, nozzles and/or injectors, shower heads, gas distribution assemblies, chamber liners, wafer holders, electronic wafer chucks, and various rings, such as focusing rings, processing rings, shielding rings, or Guard rings, and other components known to those of ordinary skill in the art. For example, machining, drilling, boring, grinding, grinding, polishing, etc. known to those skilled in the art can be performed according to known methods as needed to form the multi-layer sintered ceramic body into a predetermined shape of yttrium oxide. Zirconium ceramic sintered components for use in plasma processing chambers. At least one surface of the ceramic sintered body can be polished by the following methods (Strasbaugh polishing equipment) (polishing supplies provided by Struers, Inc.): (i) 40um alumina: to flatten the surface as needed; (ii) 12um oxide Aluminum fixed abrasive pad: 2min; (iii) 9pm diamond polyurethane pad: 8min; (iv) 6um diamond velvet: 3min, and (v) 1um diamond velvet: 3min. More specifically, at least one surface configured to face the interior of the reactor chamber can be polished to a very low surface roughness according to the disclosed methods.

The surface roughness of the sintered ceramic bodies disclosed herein can be correlated with particle generation in the processing chamber. Therefore, it is often beneficial to have reduced surface roughness. Surface roughness measurements were performed using a Keyence 3D laser scanning confocal digital microscope model VK-X250X. ISO 25178 Surface Texture (Surface Roughness Measurement) is a collection of international standards related to surface roughness analysis compatible with this microscope.

A confocal microscope with 50x magnification is used to laser scan the sample surface to capture detailed images of the sample. The parameters Sa (arithmetic mean height) and Sz (maximum height/peak to valley ratio) were measured on the sintered ceramic body. Sa represents the average roughness value calculated across the user-defined area of the sintered ceramic body surface. Sz represents the maximum peak-to-trough distance across a user-defined area on the surface of the sintered ceramic body. Ra is defined as the arithmetic mean of the absolute values of the profile height deviations recorded within the measurement length relative to the mean line. Ra measurements were performed according to ASME B46.1 and values from 20 to 45 nm were obtained across the polished surface of a ceramic sintered body with a diameter of 572 mm.

The surface roughness characteristics of Sa, Ra, and Sz are parameters well known in the basic technical field and are described, for example, in ISO standard 25178-2-2012.

The present disclosure relates to a sintered ceramic body and/or components made therefrom having a corrosion-resistant polished surface that provides a thickness of less than 90 nm as measured in accordance with ISO standard 25178-2-2012, and more preferably less than The arithmetic mean height Sa is 70nm, preferably less than 50nm, more preferably less than 25nm, and preferably less than 15nm.

The present disclosure relates to a sintered ceramic body and/or components made therefrom having a corrosion-resistant polished surface that provides a thickness of less than 3.5um as measured according to ISO standard 25178-2-2012, preferably The peak to valley height Sz is less than 2.5um, preferably less than 2um, preferably less than 1.5um, and more preferably less than 1um.

Ceramic sintered bodies/components made according to the methods disclosed herein may have mechanical properties sufficient to allow fabrication of large body sizes for use in plasma processing chambers. The components disclosed herein may have a thickness of 100 to 622mm, preferably 100 to 575mm, preferably 100 to 406mm, preferably 150 to 622mm, preferably 200mm to 622mm, preferably 300 to 622mm, preferably 150 to 575 mm, preferably 150 to 406 mm, preferably 406 to 622 mm, preferably 500 to 622 mm, and preferably 406 to 575 mm, preferably 450 to 622 mm, each relative to the longest extension of the sintered body. Generally speaking, the yttria-zirconia ceramic sintered bodies disclosed herein have a disk shape with the longest extension being the diameter.

The methods disclosed herein provide high purity, improved control over the amount of porosity, higher density, improved mechanical strength, thereby providing handleability of corrosion-resistant ceramic sintered components, particularly for those greater than, for example, 200 mm across the longest extended dimension. of these ceramic bodies and reduce oxygen vacancies in the crystal lattice of corrosion-resistant ceramic sintered components. Mix directly from calcined powders without the need for sintering aids The material-forming sintered body provides a yttria-zirconia ceramic sintered body that does not contain or substantially contains no sintering aids disclosed herein.

efficacy

Figure 2 depicts x-ray diffraction results from a powder calcination study of an exemplary yttria-zirconia calcined powder mixture of 80 mole % yttria and 20 mole % zirconia powder batch composition. The exemplary powder mixture of Figure 2a) is calcined from 800°C to 850°C for 4 to 6 hours, while the exemplary powder mixture of Figure 2b) is calcined from 850°C to 900°C for 6 to 8 hours. A tetragonal phase corresponding to zirconia and a c-type cubic phase corresponding to yttria were observed in the XRD pattern of Figure 2a), indicating that the calcined powder mixture contains crystalline yttria and zirconia powder. Figure 2b) also depicts the crystalline phase of Figure 2a), which further contains a small amount of solid solution cubic phase of yttrium zirconium oxide, which is observed at higher calcination temperatures and longer calcination times, indicating that yttrium oxide and oxidation reaction between zirconium. In some embodiments, mixtures of calcined powders containing starting powders with yttria and zirconium oxide are preferred. Further embodiments may include starting powders of yttrium oxide and zirconium oxide as the major phase, and a cubic phase of yttrium zirconium oxide as the minor phase. All x-ray diffraction (XRD) were performed using a PAAnlytical Aeris model XRD capable of identifying crystalline phases to approximately +/-2 volume %.

Calcination provides modification and optimization of the particle size distribution (PSD) and specific surface area (which are related to the starting powder and/or the calcined powder mixture, surface area and specific surface area (SSA) are used interchangeably herein). Table 5 discloses the calcination conditions and the resulting powder surface area, and particle size distribution of the calcined powder mixture of 80 mole % yttrium oxide and 20 mole % zirconia disclosed herein.

table 5

Calcining at temperatures of 1400°C or higher may not be preferred because it results in low specific surface area (SSA) and very large particle sizes. Preferably, the SSA is not less than 1.75 m2/g, more preferably not less than 2 m2/g of the calcined powder mixture. The large particle size measured at 1400°C represents particle agglomeration, which may inhibit powder flow and mixing. Therefore, it is preferable to calcine at a temperature of 1300°C or lower, more preferably not lower than 600°C and not higher than 1200°C, preferably not lower than 600°C and not higher than 1200°C in an oxidizing environment. Calcining temperature of 1100℃. Any of the starting powder, powder mixture, and calcined powder mixture may optionally be sieved according to known methods at various process steps using any number of sieves (which may have, for example, 45um to 400um openings), and blending and/or dry grinding are performed, but there is no limit on the repetition or order.

Figure 3 illustrates x-ray diffraction results of an exemplary yttria-zirconia ceramic sintered body having a composition of approximately 80 mole % yttria and approximately 20 mole % zirconia. The object is sintered at a temperature of about 1500°C and a pressure of about 30 MPa for 30 minutes according to the method disclosed herein. X-ray diffraction confirmed the presence of a cubic crystal phase including at least one of fluorite and c-type yttrium oxide crystal structures.

Figure 4 shows the x-ray diffraction results of the exemplary yttria-zirconia ceramic sintered body of Figure 3 after being annealed at 1550° C. for 8 hours in an oxidizing environment. X-ray diffraction confirmed that the crystalline phase existing after annealing did not change from that in Figure 3.

Figure 5 depicts x-ray diffraction results for an exemplary yttria-zirconia ceramic sintered body across a range of annealing conditions from no anneal (A) to annealing temperatures of 1100°C (B) to 1550°C (C). The increase in peak height and decrease in peak width represent the increase in crystallinity of the yttria-zirconia sintered body at higher annealing temperatures.

Figures 6a) through 6d) show 5000x SEM micrographs of exemplary sintered microstructures of yttria-zirconia sintered bodies as disclosed herein. Figure 6a) shows an exemplary microstructure after sintering at a temperature of 1500°C and a pressure of 30MPa for 30 minutes; Figure 6b) shows an exemplary microstructure after sintering according to a) and annealing at 1000°C for 8 hours; Figure 6c) shows an exemplary microstructure after sintering according to a) and annealing at 1200°C for 8 hours, and Figure 6d) shows an exemplary microstructure after sintering according to a) and annealing at 1400°C for 8 hours. No pores are visible in the microstructure, which indicates a very high (>98.5% of theoretical) density.

Very small particle sizes can be observed in the SEM images of Figures 6a) to 6d). Particle size was measured according to the Heyn Linear Intercept Procedure described in ASTM standard E112-2010 "Standard Test Method for Determining Average Grain Size". The maximum particle size may be less than 8um, preferably less than 5um, and preferably 3 to 8um. Particle size measured as "um" herein means a value of 10 ^-6 meters. The average particle size measured is 0.5 to less than 3um, preferably 0.5 to less than 2um, preferably 0.5 to 1um, and more preferably 0.4 to less than 2um. The SEM micrograph of Figure 6a) (unannealed) was measured to have an average particle size of approximately 0.7um, while the micrograph of Figure 6d) (annealed at 1400°C for 8 hours) was measured to have an average particle size very similar to that of Figure a) Similar particle size, with an average particle size of about 0.8um. These fine particle sizes provide yttria-zirconia ceramic sintered bodies with improved mechanical strength and resistance to microcracking, and/or spalling during machining and use as components in plasma processing chambers.

When used in semiconductor processing applications, the combination of high density/low porosity, small particle size, and high purity of yttria zirconia ceramic sintered bodies (and components made therefrom) provides advantages over other ceramics. Advantages of porcelain materials. These advantages include enhanced resistance to erosion and corrosive effects caused by plasma etching and deposition processes (plasma resistance) and improved mechanical strength.

Embodiments disclosed herein include ceramic sintered bodies and components made therefrom that are adapted for use in the exemplary semiconductor processing chambers shown in Figures 7 and 8.

As shown in the cross-sectional view of Figure 7, embodiments of the technology disclosed herein may include a semiconductor processing system 9500, also labeled a processing system. Treatment system 9500 may include a remote plasma region. The remote plasma region may include a plasma source 9502, also designated as a remote plasma source ("RPS").

Processing system 9500, which may be representative of a capacitively coupled plasma processing apparatus, includes a vacuum chamber 9550 having a corrosion-resistant chamber liner (not shown), a vacuum source, and a chuck 9508 on which wafer 50 is supported. Also labeled as semiconductor substrate. Cover ring 9514 and top shield ring 9512 surround wafer 50 and positioning plate 9509 . A window or cover 9507 forms the upper wall of the vacuum chamber 9550. Window/cover 9507, gas distribution system 9506, cover ring 9514, top shield ring 9512, focus ring (not shown), chamber liner (not shown), and positioning plate 9509 may be fully or partially disclosed herein. An embodiment of a ceramic sintered body is made, wherein the ceramic sintered body contains no less than 75 mol% to no more than 95 mol% of yttrium oxide, and no less than 5 mol% to no more than 25 mol% of zirconia, and compositions within the scope disclosed herein. The terms "window" and "lid" are considered to have the same meaning and are therefore used synonymously herein. Embodiments of ring assemblies (such as cover rings, shielding rings, process rings, etc.) may include any number of ring assemblies as is known to one of ordinary skill in the art.

The remote plasma source 9502 is disposed outside the window 9507 of the chamber 9550 for receiving the wafer 50 to be processed. The distal plasma region may be in fluid communication with the vacuum chamber 9550 via a gas delivery system 9506. In chamber 9550, capacitively coupled plasma can be generated by supplying process gas to chamber 9550 and supplying high frequency power to plasma source 9502. By using the capacitively coupled plasma so generated, the wafer 50 Predetermined plasma treatment is carried out. Planar antennas with predetermined patterns are widely used as high-frequency antennas in the capacitive coupling processing system 9500.

As shown in the cross-sectional view of Figure 8, another embodiment of the technology disclosed herein may include a semiconductor processing system 9600, also referred to as a processing system. A processing system 9600, which may be representative of an inductively coupled plasma processing apparatus, includes a vacuum chamber 9650, a vacuum source, and a chuck 9608 on which a wafer 50, also designated a semiconductor substrate, is supported. The nozzle 9700 forms the upper wall or is installed below the upper wall of the vacuum chamber 9650. The ceramic nozzle 9700 includes a gas plenum in fluid communication with a plurality of nozzle gas outlets for supplying process gas to the interior of the vacuum chamber 9650. Shower head 9700 is in fluid communication with gas delivery system 9606. Additionally, showerhead 9700 may include a central opening configured to receive a central gas injector, also equivalently referred to as nozzle 9714. The RF energy source energizes the process gas into a plasma state to process the semiconductor substrate. The flow rate of the process gas supplied by the central gas injector 9714 and the flow rate of the process gas supplied by the ceramic nozzle can be independently controlled. The showerhead or gas distribution plate 9700, the gas delivery system 9606, and the central gas injector 9714 may be made from embodiments of the ceramic sintered bodies disclosed herein that include no less than 75 mole % and no more than 95 mole %. Yttrium oxide, no less than 5 mol% to no more than 25 mol% zirconium oxide, and compositions within these ranges disclosed herein.

System 9600 may further include an electrostatic chuck 9608 designed to hold wafer 50 . The chuck 9608 may include a positioning plate 9609 for supporting the wafer 50 . Paw 9609 may be formed from a dielectric material and may have chucking electrodes disposed within the puck adjacent a support surface of puck 9609 to electrostatically hold wafer 50 while it is disposed on puck 9609 round. The chuck 9608 may include: a base 9611 having an annular extension to support the positioning plate 9609; and a shaft 9610 disposed between the base and the positioning plate to support the positioning plate above the base such that the positioning plate A gap is formed between 9609 and the base 9610, in which the axis 9610 is supported near the peripheral edge of the positioning plate 9609 Support the positioning plate. The chuck 9608 and the positioning plate 9609 can be made from embodiments of the ceramic sintered body disclosed herein, the ceramic sintered body comprising no less than 75 mole % and no more than 95 mole % yttrium oxide, no less than 5 mole % and No more than 25 mole % zirconia, and compositions within these ranges disclosed herein. The chuck 9608 may include an electrostatic chuck (ESC) and other embodiments beyond those disclosed by those of ordinary skill in the art.

Part of the surface of the nozzle 9700 may be covered by the shielding ring 9712. Part of the surface of the nozzle 9700 (especially the radial side of the surface of the nozzle 9700) may be covered by the top shielding ring 9710. Shield ring 9712 and top shield ring 9710 may be made from embodiments of the ceramic sintered bodies disclosed herein that include no less than 75 mole % to no more than 95 mole % yttrium oxide, no less than 5 mole % to no more than 25 mole % zirconia, and compositions within these ranges disclosed herein.

Part of the support surface of positioning plate 9609 may be covered by covering ring 9614. Other portions of the surface of positioning plate 9609 may be covered by top shield ring 9612 and/or shield ring 9613. Shield ring 9613, cover ring 9614, and top shield ring 9612 may be made from embodiments of the ceramic sintered bodies disclosed herein that include no less than 75 mole % to no more than 95 mole % yttrium oxide, no Less than 5 mol% to no more than 25 mol% zirconia, and compositions within these ranges disclosed herein.

Embodiments of the ceramic sintered bodies disclosed herein may be combined in any particular ceramic sintered body. Accordingly, two or more of the properties disclosed herein may be combined to describe the ceramic sintered body in greater detail, for example, as outlined in the Examples.

The inventors determined that the above ceramic sintered bodies and related corrosion-resistant sintered components have improved performance in etching and deposition processes, have improved processing capabilities, and can be readily used to prepare components for use in plasma processing chambers material.

As mentioned above, the yttrium oxide and zirconium oxide materials used to date for plasma processing chamber components have had a major problem, which is that under harsh etching and deposition conditions, they can produce particles that contaminate the products to be processed. Due to the inherent low mechanical strength of yttria and zirconia, it is difficult to produce large-size (maximum size or diameter 200mm to 622mm) solid, pure-phase, high-strength solids formed from high-purity sintered bodies containing yttria and zirconia. parts, but at the same time they do not have defects, cracks, or microcracks (cracks not visible to the naked eye).

In contrast, the present technology provides a new concept for fabricating corrosion-resistant components for plasma processing chambers and focuses on purity, density, crystal phase, particle size, and processability. According to the present disclosure, in addition to the bulk (percentage) porosity characteristics of the yttrium oxide and zirconium oxide materials disclosed herein, it is determined that the porosity characteristics, density, and particle size can also have an important impact on etching and deposition stability.

The aforementioned ceramic sintered bodies, including crystal phases of yttrium oxide and zirconium oxide and combinations thereof, may themselves be useful in the manufacture of large corrosion-resistant components ranging from 10 mm to 622 mm in size relative to the maximum extension of the sintered body. The large component sizes described herein can be achieved by the increased density, low porosity, and fine particle size of the ceramic sintered bodies from which the chamber components can be made.

Using ceramic sintered bodies made from crystalline phases of yttria and zirconium oxide and combinations thereof in semiconductor processing chambers, the conductive sintered material has been shown to outperform other sintered materials when subjected to halogen-based plasma processing conditions and deposition conditions. The material's improved resistance to plasma corrosion and erosion ("plasma resistance").

Example

The following examples are included to more clearly demonstrate the overall nature of the present disclosure. These examples are illustrative and do not limit the disclosure.

Example 1 (Sample 1, Table 1) Yttrium oxide powder with a surface area of 2 to 4 m ² /g, and zirconia powder with a surface area of 6 to 8 m ² /g were weighed and combined to produce a ratio of 80 mol%. A powder mixture of yttria and 20 mol% zirconia (87.3% yttria and 12.7% zirconia by weight). The purity of yttrium oxide powder is greater than about 99.998%, and the purity of zirconia powder is greater than about 99.79%, as measured using the ICP-MS method disclosed herein. 50% by weight of powder ethanol and 100% by weight of powder zirconia medium were added to the powder mixture to form a slurry. The slurry was stand/tumble mixed at RPM of 10 to 30 rpm for 12 hours. Ethanol is extracted from the slurry using a rotary evaporator at a temperature of approximately 75°C until dry. Any of the starting powder, powder mixture, and calcined powder mixture may optionally be sieved according to known methods at various process steps using any number of sieves (which may have, for example, 45um to 400um openings), and blending and/or dry grinding are performed, but there is no limit on the repetition or order.

The powder mixture was calcined in air at 850°C for 6 hours. Then, according to the method disclosed herein, the calcined powder mixture was sintered under vacuum at a sintering temperature of 1625°C and a pressure of 25 MPa for a sintering time of 90 minutes to form a disc-shaped ceramic sintered body with a diameter of 406 mm. The ceramic sintered body was annealed at 1400°C for about 8 hours. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.10 g/cc, which corresponds to the theoretical density of a ceramic sintered body containing 80 mol% yttrium oxide/20 mol% zirconia (herein referred to as The theoretical density revealed is 99.4% of 5.13g/cc). The ceramic sintered body contains an amount of porosity (herein also referred to as volume porosity, Vp) of 0.6%. Density measurements across the ceramic sintered body determined that the density difference across the diameter (relative to the theoretical density) was no greater than 2%.

Example 2 (Sample 2, Table 1) A disc-shaped ceramic sintered body with a diameter of 406 mm was formed according to the materials and methods disclosed in Example 1, but the difference was that no annealing was performed. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.13g/cc, which corresponds to a sample containing 80 moles 100% of the theoretical density of the ceramic sintered body of 10 mol% yttrium oxide/20 mol% zirconia. Ceramic sintered bodies contain no porosity (also referred to herein as volume porosity, Vp).

Example 3 (Sample 3, Table 1) A powder mixture was formed and dried according to the amounts, materials, and methods of Example 1. Calcination of the powder mixture was carried out in air at 950°C for 6 hours. Then, according to the method disclosed herein, the calcined powder mixture is sintered under vacuum at a sintering temperature of 1600°C and a pressure of 15 MPa for a sintering time of 30 minutes to form a disc-shaped ceramic sintered body with a diameter of 150 mm. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.11 g/cc, which corresponds to 99.6% of the theoretical density of a ceramic sintered body containing 80 mol% yttrium oxide/20 mol% zirconia. . The ceramic sintered body contains a porosity in the amount of 0.4% (also referred to herein as volume porosity, Vp).

Example 4 (Sample 4, Table 1) A ceramic sintered body was formed according to the materials and methods of Example 3. The ceramic sintered body was annealed at 1200°C for 8 hours in an oxygen-containing environment. Density measurements were performed according to ASTM B962-17 and the average density was measured to be 5.11 g/cc, which corresponds to the theoretical density of an annealed ceramic sintered body containing 80 mol% yttrium oxide/20 mol% zirconia. 99.6%. The ceramic sintered body contains a porosity in the amount of 0.4% (also referred to herein as volume porosity, Vp).

Example 5 (Sample 5, Table 1) A ceramic sintered body was formed according to the materials and methods of Example 3. The ceramic sintered body was further annealed at 1300°C for 8 hours in an oxygen-containing environment. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.09 g/cc, which corresponds to 99.2% of the theoretical density of a ceramic sintered body containing 80 mol% yttrium oxide/20 mol% zirconia. . The ceramic sintered body contains a porosity in the amount of 0.8% (also referred to herein as volume porosity, Vp).

Example 6 (Sample 6, Table 1) A powder mixture was formed and dried according to the materials and methods of Example 1, except that 35% by weight of the powder ethanol and 100% by weight of the zirconia medium were added to the powder mixture. Form a slurry. Calcination was carried out in air at 850°C for 6 hours. Then, according to the method disclosed herein, the calcined powder mixture is sintered under vacuum at a sintering temperature of 1450°C and a pressure of 20 MPa for a sintering time of 30 minutes to form a disc-shaped ceramic sintered body with a diameter of 150 mm. The ceramic sintered body was annealed at 1300° C. for 8 hours in an oxygen-containing environment. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.11 g/cc, which corresponds to 99.6% of the theoretical density of a ceramic sintered body containing 80 mol% yttrium oxide/20 mol% zirconia. . The ceramic sintered body contains a porosity in the amount of 0.4% (also referred to herein as volume porosity, Vp).

Example 7 (Sample 7 of Table 1) A calcined powder mixture was formed as disclosed in Example 1. Then, according to the method disclosed herein, the calcined powder mixture is sintered under vacuum at a sintering temperature of 1500°C and a pressure of 30 MPa for a sintering time of 30 minutes to form a disc-shaped ceramic sintered body with a diameter of 100 mm. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.13 g/cc, which corresponds to 100% of the theoretical density of a ceramic sintered body containing 80 mol% yttrium oxide/20 mol% zirconia. . Ceramic sintered bodies contain no porosity.

Example 8 (Sample 8 of Table 1) Yttrium oxide powder with a surface area of 6 to 8 m ² /g, and zirconium oxide powder with a surface area of 6 to 8 m ² /g were weighed and combined to produce a ratio of 90 mol%. A powder mixture of yttrium oxide and 10 mol% zirconia. A slurry was formed by adding approximately 35 wt% ethanol relative to the weight of the powder mixture and adding zirconia media at a loading of 100% relative to the weight of the powder. The powder mixture was ball milled at about 125 RPM for about 12 hours. The powder mixture was calcined in air at 1000°C for 8 hours. Then, according to the method disclosed herein, the calcined powder mixture is sintered under vacuum at a sintering temperature of 1500°C and a pressure of 30 MPa for a sintering time of 30 minutes to form a disc-shaped ceramic sintered body with a diameter of 100 mm. Density measurements were performed according to ASTM B962-17, and the average density was measured to be 5.08 g/cc, which corresponds to 100% of the theoretical density of a ceramic sintered body containing 90 mol% yttrium oxide/10 mol% zirconia. . Ceramic sintered bodies contain no porosity.

Examples 9 and 10 A calcined powder mixture was prepared according to the disclosure of Example 1. According to the method disclosed herein, the calcined powder mixture is sintered under vacuum at a sintering temperature of 1600°C and a pressure of 15MPa for a sintering time of 45 minutes to form a disc-shaped ceramic sintered body with a diameter of 406mm corresponding to sample 9 . The ceramic sintered body of Sample 9 was further annealed at 1400°C for 8 hours in air. According to the method disclosed in this article, a disc-shaped ceramic sintered body with a diameter of 406 mm is formed by sintering under vacuum at a sintering temperature of 1625°C and a pressure of 20 MPa for a sintering time of 60 minutes. Thus, from Example 1 The calcined powder mixture formed Sample 10. The dielectric constant and loss factor were measured according to ASTM D-150 at 1MHz frequency and ambient temperature, and the results are listed below. Within the range of measurements performed, the same dielectric performance was measured for annealed yttria-zirconia ceramic sintered bodies and for those without annealing.

Example 11 A calcined powder mixture was formed according to the disclosure of Example 1. According to the method disclosed in this article, the calcined powder mixture is sintered under vacuum at a sintering temperature of 1625°C and a pressure of 15 MPa for a sintering time of 90 minutes to form a complete 80-minute disc-shaped tube with a diameter of 572 mm that is easy to handle. Mol% yttrium oxide, 20 mol% zirconia ceramic sintered body. The sintered ceramic body was annealed at 1400°C for 10 minutes in an oxygen-containing atmosphere. Thereafter, the sintered body was subjected to density measurement according to ASTM B962-17. The measured density is 5.13 g/cc, which corresponds to approximately 100% of the theoretical density of a sintered body containing 80 mol% yttrium oxide and 20 mol% zirconium oxide (taken as 5.13 g/cc in this article). Surface roughness measurements were performed using a Keyence 3D laser scanning confocal digital microscope model VK-X250X. ISO 25178 Surface Texture (Surface Roughness Measurement) is a collection of international standards related to surface roughness analysis compatible with this microscope. The parameters Sa (arithmetic mean height) and Sz (maximum height/peak to valley ratio) were measured on the sintered ceramic body. Sa represents the average roughness value calculated across the user-defined area of the sintered ceramic body surface. Sz represents the maximum peak-to-trough distance across a user-defined area on the surface of the sintered ceramic body. The surface roughness characteristics of Sa and Sz are parameters well known in the basic technical field and are described, for example, in ISO standard 25178-2-2012.

According to ISO standard 25178-2-2012, the Sa value is less than 90 nm, preferably less than 70 nm, more preferably less than 50 nm, preferably less than 25 nm, and preferably less than 15 nm, measured on the polished surface.

An Sz value of less than 3.5um, preferably less than 2.5um, preferably less than 2um, preferably less than 1.5um, and more preferably less than 1um measured on a polished surface according to ISO standard 25178-2-2012 .

Although shown and described above with reference to certain specific embodiments and examples, the present disclosure is not intended to be limited to the details shown. Rather, various modifications may be made in the details that are within the scope and scope of equivalents to the patented claims and without departing from the spirit of the disclosure. It is expressly intended that, for example, all references to broad ranges in this document include within their scope all narrower ranges that fall within the broader ranges.

Claims (48)

A ceramic sintered body, which contains: yttrium oxide and zirconium oxide, wherein the ceramic sintered body contains no less than 75 mol% to no more than 95 mol% of yttrium oxide, and no less than 5 mol% to no more than 25 mol%. % of zirconia, wherein the ceramic sintered body contains an amount of porosity less than 2% by volume, wherein the density of the ceramic sintered body does not vary by more than 2% relative to the theoretical density in the largest dimension, and wherein the ceramic sintered body has a The average particle size measured by ASTM E112-2010 is 0.4 to less than 2um. The ceramic sintered body of claim 1, which has at least one surface containing yttria and zirconium oxide, wherein the at least one surface is polished and contains a porosity of less than 2% based on the pore area of the at least one surface. The ceramic sintered body of claim 2, wherein the porosity measured on the polished surface extends throughout the ceramic sintered body. For example, the ceramic sintered body of claim 1 contains yttrium oxide in an amount of not less than 75 mol% and not more than 85 mol%, and zirconium oxide in an amount of not less than 15 mol% and not more than 25 mol%. For example, the ceramic sintered body of claim 1 contains no less than 77 mol% to no more than 83 mol% of yttrium oxide, and no less than 17 mol% to no more than 23 mol% of zirconia. For example, the ceramic sintered body of claim 1 contains no less than 78 mol% to no more than 82 mol% of yttrium oxide, and no less than 18 mol% to no more than 22 mol% of zirconia. The ceramic sintered body of any one of claims 4 to 6 has a density of 5.01 g/cc to 5.13 g/cc measured according to ASTM B962-17. The ceramic sintered body of any one of claims 4 to 6 has a hardness of not less than 8.5 to 14.5 GPa measured according to ASTM standard C1327. The ceramic sintered body of any one of claims 1 to 6, excluding HfO2 and SiO2, has a purity of greater than 99.99% relative to 100% purity measured using the ICP-MS method. The ceramic sintered body of any one of claims 1 to 6, wherein the ceramic sintered body has a total impurity content of less than 100 ppm. The ceramic sintered body of any one of claims 1 to 6, wherein the at least one crystal phase includes a cubic solid solution, and the cubic solid solution system is selected from the group consisting of fluorite, c-type cube and combinations thereof. The ceramic sintered body of any one of claims 1 to 6, which has a pore diameter measured across the polished surface of not less than 0.1 to not more than 5 μm. The ceramic sintered body of any one of claims 1 to 6, which has a pore diameter measured across the polished surface of not less than 0.1 to not more than 3 μm. The ceramic sintered body of any one of claims 1 to 6, which has at least one surface with an average particle diameter measured according to ASTM E112-2010 of 0.75 μm to 6 μm. The ceramic sintered body according to any one of claims 1 to 6, which contains a c-type cubic solid solution phase. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 100 mm to 622 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 100 to 575 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 100 to 406 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 150 to 622 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 150 to 575 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 150 to 406 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 406 to 622 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6 has a maximum dimension of 406 to 575 mm, each of which is the longest extension relative to the sintered body. The ceramic sintered body of any one of claims 1 to 6, wherein the ceramic sintered system is selected from the group consisting of: a window in a plasma processing chamber, an RF window, a cover, a focusing ring, a shielding ring, Nozzles, gas injectors, spray heads, gas distribution plates, chamber liners, chucks, electrostatic chucks, positioning plates and cover rings. A method of manufacturing a ceramic sintered body, which method includes the following steps: a. combining powders of yttria and zirconium oxide to form a powder mixture; b. raising the temperature of the powder mixture to a calcination temperature by applying heat to calcine the powder mixture and maintain the calcining temperature to form a calcined powder mixture; c. disposing the calcined powder mixture within a volume defined by the tool set of the sintering equipment and creating vacuum conditions within the volume; d. applying pressure to the calcined powder mixture while heating to a sintering temperature, and sintering to form the ceramic sintered body; and e. reduce the temperature of the ceramic sintered body. The method of claim 25, further comprising the following steps: f. Optionally annealing the ceramic sintered body by applying heat to increase the temperature of the ceramic sintered body to reach an annealing temperature to form an annealed ceramic sintered body; and g. reduce the temperature of the annealed ceramic sintered body. The method of claim 25, further comprising the following steps: h. Optionally machining the ceramic sintered body to form a ceramic sintered body assembly in a plasma processing chamber. The method of claim 27, wherein the ceramic sintered body component is selected from the group consisting of: window, RF window, cover, focus ring, shielding ring, nozzle, gas injector, shower head, gas distribution plate, chamber liner, Chuck, electrostatic chuck, positioning plate and covering ring. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a purity of 99.99% or higher relative to 100% purity as measured using an ICP-MS method. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 2 to 14 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 2 to 12 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 2 to 10 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 2 to 8 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 2 to 6 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 2.5 to 10 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) measured according to ASTM C1274 of 3 to 10 m ² /g. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) of 4 to 10 m ² /g measured according to ASTM C1274. The method of any one of claims 25 to 28, wherein the calcined powder mixture has a specific surface area (SSA) of 2 to 5 m ² / measured according to ASTM C1274. The method of any one of claims 25 to 28, wherein the calcination temperature is 600°C to 1200°C. The method of any one of claims 25 to 28, wherein the pressure is 10 to 60 MPa. The method of any one of claims 25 to 28, wherein the pressure is 10 to 50 MPa. The method of any one of claims 25 to 28, wherein the pressure is 10 to 40 MPa. The method of any one of claims 25 to 28, wherein the pressure is 10 to 30 MPa. The method of any one of claims 25 to 28, wherein the pressure is 15 to 40 MPa. The method of any one of claims 25 to 28, wherein the pressure is 15 to 30 MPa. The method of any one of claims 25 to 28, wherein the pressure is 15 to 25 MPa. The method of any one of claims 25 to 28, wherein the sintering temperature is 1200°C to 1700°C. The method of any one of claims 25 to 28, wherein the annealing temperature is 800°C to 1500°C.